Instruction Book

Welcome to the World of Radio Control Model Airplanes!

READ THROUGH THIS INSTRUCTION
BOOKLET FIRST. IT CONTAINS IMPORTANT
INSTRUCTIONS AND WARNINGS CONCERN-
ING THE BUILDING AND USE OF THIS
MODEL.

WARNING!
This R/C kit and the model you will build is not a toy! It is capable of serious
bodily harm and property damage. IT IS YOUR RESPONSIBILITY AND YOURS
ALONE — to build this kit correctly, properly install all R/C components and flying
gear (engine, tank, pushrods, etc.) and to test the model and fly it only with experi-
enced, competent help in accordance with all safety standards and common
sense as set down in the Academy of Model Aeronautics Safety Code. It is sug-
gested that you join the AMA and become properly insured before you attempt to
fly this model. IF YOU ARE JUST STARTING R/C MODELING, CONSULT YOUR
LOCAL HOBBY SHOP OR WRITE TO THE ACADEMY OF MODEL AERONAUTICS
TO FIND AN EXPERIENCED INSTRUCTOR IN YOUR AREA.
Academy of Model Aeronautics
5151 East Memorial Drive
Muncie, IN 47302-9252
(800) 435-9262
PO BOX 788 URBANA ILLINOIS 61801
 TABLE OF CONTENTS
GENERAL COMMENTS . . . . . . . . . . . . . . . . . . . . 2 INSTALL TRAILING EDGE, AILERONS AND
TORQUE RODS (WING B ONLY) . . . . . . . . . . . 20
BUILDING PRECAUTIONS . . . . . . . . . . . . . . . . . 3
INSTALL THE WING TIPS . . . . . . . . . . . . . . . . . 21
GLUES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
SAND THE WING SMOOTH . . . . . . . . . . . . . . . 22
BUILDING HINTS . . . . . . . . . . . . . . . . . . . . . . . . . 4
INSTALL THE WING PLATES . . . . . . . . . . . . . . 22
ITEMS NEEDED . . . . . . . . . . . . . . . . . . . . . . . . . . 4
TRIAL FIT THE WING IN THE SADDLE . . . . 22
TOOLS OR SUPPLIES NEEDED . . . . . . . . . . . . . 4
MOUNT THE ENGINE . . . . . . . . . . . . . . . . . . . . 23
SPECIAL NOTE ON ENGINES . . . . . . . . . . . . . . 4
PARTS IDENTIFICATION DRAWINGS 5 INSTALL THE SERVOS . . . . . . . . . . . . . . . . . . . 24

GET READY TO BUILD . . . . . . . . . . . . . . . . . . . . 6 INSTALL NYLON CONTROL HORNS . . . . . . . 25

BUILD THE FUSELAGE SIDES . . . . . . . . . . . . . 7 PUSHRODS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

ASSEMBLE THE FUSELAGE . . . . . . . . . . . . . . . 8 BALANCE THE AIRPLANE LATERALLY . . . . 29

INSTALL THE WINDSHIELD AND HATCH .. 10 ADD THE FUSELAGE TOP . . . . . . . . . . . . . . . . 29

MOUNT THE ENGINE BEAMS AND SAND THE FUSELAGE . . . . . . . . . . . . . . . . . . . 30

BREAKAWAY PLATES . . . . . . . . . . . . . . . . . . . . 11 FUELPROOF THE ENGINE AND FUEL
INSTALL THE LANDING GEAR . . . . . . . . . . . . 12 TANK COMPARTMENTS . . . . . . . . . . . . . 30

PREPARE THE NOSE GEAR . . . . . . . . . . . . . . . 12 PREPARE THE MODEL FOR COVERING . . . . 30

CUT THE NOSE GEAR PUSHROD OPENING . 12 COVER THE STABILIZER . . . . . . . . . . . . . . . . . 30

CUT THE PUSHROD EXIT SLOTS FOR THE COVER THE FIN, RUDDER AND ELEVATOR . 30
RUDDER AND ELEVATOR . . . . . . . . . . . . . . . . 13 COVER THE FUSELAGE . . . . . . . . . . . . . . . . . . 30
BUILD AND INSTALL THE COVER THE WING . . . . . . . . . . . . . . . . . . . . . . . 31
"TAIL FEATHERS" . . . . . . . . . . . . . . . . . . . . . . . 13
ADD "WASHOUT" AT THE WING TIPS . . . . . . 31
MAKE THE HINGES . . . . . . . . . . . . . . . . . . . . . . 14
FINAL ASSEMBLY . . . . . . . . . . . . . . . . . . . . . . . 32
MARK THE HINGE LOCATIONS . . . . . . . . . . . 14
BALANCE YOUR MODEL . . . . . . . . . . . . . . . . . 34
CUT THE HINGE SLOTS . . . . . . . . . . . . . . . . . . 14
FLYING ................................. 34
MOUNT THE STAB ON THE FUSE . . . . . . . . . 14
AMA SAFETY CODE . . . . . . . . . . . . . . . . . . . . . 36
MOUNT THE FIN TO THE STAB . . . . . . . . . . . 15
CHANGING FROM 3 TO 4
BUILD THE WING PANELS . . . . . . . . . . . . . . . 16 CHANNEL VERSION . . . . . . . . . . . . . . . . . . . . 37
JOIN THE WING PANELS . . . . . . . . . . . . . . . . . 18 FLIGHT PROBLEMS CHART . . . . . . . . . . . . . . . 38
INSTALL THE CENTER RIBS AND GLOSSARY .............................. 39
BOTTOM SHEETING . . . . . . . . . . . . . . . . . . . . . 19
PARTS LIST . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
INSTALL TAPERED TRAILING EDGE
(WING A ONLY) . . . . . . . . . . . . . . . . . . . . . . . . . . 19

GENERAL COMMENTS
Congratulations on your purchase of Great Our line of R/C kits is the fastest growing and
Planes' PT40, the Perfect Trainer! You now own the we believe the finest in the nation. As a result of
easiest building, easiest flying trainer on the market. intensive testing, combined with our years of experi-
By following these instructions and by referring to ence, we know that a well built Great Planes' kit
the plans, you will have a model you can be proud of will fly right. But that means:
and one that will fly, almost by itself!
1. You must build the plane according to the plans the part of the plans you are working on to prevent
and instructions glues from sticking to the plans Remember a careful
builder will build a warp-free, straight model that
2. You must take time to build straight, true and will fly as it was designed to
strong.
Read and obey cautions, warnings and direc-
3. You must use a proper R/C radio that is in first tions on such items as glues, paints and other mater-
class condition, the correct sized engine and correct ials These are often TOXIC to the human body in
components (fuel tank, wheels, etc) throughout terms of breathing and/or touch Be especially cauti-
your building process ous of cyanoacrylate glues that dry almost instantly
4. You must properly install all R/C and other and bond with great power (also known as CA glues)
components so that the model operates properly on They require special care since they can be extremely
the ground. dangerous if they get into the eyes or on human skin
Watch for ventilation warnings and observe them
5. You must test the operation of the model before Keep small children and pets away from all building
the first and each successive flight to insure that all and finishing materials. Keep your building area safe
equipment is operating and you must make certain and clean
that the model has remained structurally sound.
We urge you to read through these instructions,
6 You must fly the model only with competent identify all the parts, mark them with their names,
help from a well experienced R/C pilot if you are not letters or numbers and look over the plans so you
already an experienced and knowledgeable R/C pilot become familiar with what the model will look like
at this time. and what the names of the different parts are
Throughout the instructions we will be referring to
Note- We, as the kit manufacturer, can provide the various parts of the model as they are called out
you with a top quality kit and great instructions, but on the plan There is a glossary in the back of these
ultimately the quality and flyability of your finished instructions if you are unfamiliar with any words or
model depends on how you build it, therefore, we part names. Refer to it for help.
cannot in any way guarantee the performance of your
completed model, and no representations are expres- If when you are identifying the parts you find
sed or implied as to the performance or safety of your that a part is missing or broken, please let us know
completed model. about it before you start building and we will correct
the problem
BUILDING PRECAUTIONS
CONSTRUCTION PROCEDURE
Keep in mind that it is impossible for us to
guide you specifically as to every possible matter that GLUES (ADHESIVES)
might come up as you build The fun and challenge
is to tackle the problem, using the plans and instruc- If you look at the "ITEMS NEEDED" list you
tions for resources as well as the assistance and ad- will see that we recommend only two basic types of
vice of fellow builders and your local hobby dealer. glue for building the PT-40...CA glue and epoxy.

The plans are the basic guide to building Do CA (cyanoacrylate) glues are great for model
not alter or modify the model as represented by building because they set fast Rather than pinning
these plans Follow the step by step procedures given glued joints together and waiting for hours while the
in the building instructions. glue dries, CA glues will harden in a few seconds
while you hold the parts together Thin CA runs
Invest in the proper tools for building Knives, right into a good fitting Joint, so you can assemble
drills and bits, saws, rulers, pliers and screw drivers the parts first, then apply thin CA Thick CA is more
are but a few of the tools you will need Check the like syrup and it will not harden until you press the
list of tools needed in this book and seek the advice two parts together, squeezing the glue out to a thin
of your dealer. layer A related and very handy product is CA Ac-
celerator spray (Zip Kicker or Hot Shot), and is
For best results, you should have such compo- used to instantly harden CA glue When using CA
nents as the engine, tank and radio on hand as you glues make sure the parts fit well before gluing
build for fitting and installation purposes, it is much because they don't give you a second chance
more difficult, sometimes impossible, to do a proper
building job when components are purchased and If you need time to position glued pieces cor-
fitting attempted after most of the model is com- rectly or need extra strength, use epoxy glues Epoxy
pleted Always have an eye on installation of the is normally used in the firewall and engine mount
components you intend to use as you build, take time area and when gluing the two wing panels together
to think through and prepare for the installation of Five minute epoxy (it starts to harden in 5 minutes)
those components Don't hurry! Take your time to is great for most applications If you need longer time
create a well built model that conforms to the plans use 15 or 30 minute epoxy You need not use large
Build on a large, flat surface. Use waxed paper over amounts of epoxy. Squeeze out the amounts of epoxy
and hardener that your particular brand requires. 6- 5/32" Wheel Collars
For example, some epoxies use equal amounts and 1- 6 or 8 oz. Fuel Tank
some use a 1 to 2 mixture . Mix these together. Coat 1/4 pound- #64 Rubber Bands
one piece with epoxy; squeegee the excess glue off Thin Cyanoacrylate Glue, 2 oz.
with scrap wood. The epoxy glue will work better if Thick Cyanoacrylate Glue, 1 oz.
there isn't too much oozing out at the edges of the 5 Minute Epoxy, 2.5 oz.
glued piece. Wipe off any of this excess glue. 15 or 30 minute epoxy, 2.5 oz.
Wing Seating Tape
In any case, glue is never a substitute for a Balancing Weights
good-fitting joint; once the joint is formed, use a Iron-On Covering Material (Top Flite Super
minimum amount of glue and wipe off the excess. MonoKote Recommended)
Clamp, pin or hold the joint while the glue is drying. Foam Rubber (For Cushioning Radio Receiver
Remember: Take your time and follow di- and Battery)
rections to end up with a well-built model that Radio System (3 or 4 Channel)
is straight and true. Engine (.25-.40 2-Cycle or .30 to .45 4-Cycle)
Fuel Line, medium size
BUILDING HINTS Chicken Stick or Electric Starter
Glow Plug Clip
Your work area ideally should be large and com-
Glow Plug Battery
fortable enough for you to work without having to
put everything away every night. (The kitchen table
is not recommended!) The key to a straight fuselage TOOLS OR SUPPLIES NEEDED:
and warp-free wings is a straight, flat building board Hand or Electric Drill
or work bench. Remember, your model is only as Drill Bits 3/16", 5/64", 3/32", 1/8", 3/16", 7/32", 5/16")
straight as the board you build on. Have all your Sanding Block or T- Bar
tools handy and your building will go much easier. Sealing Iron
Build over the plans when instructed. Cover Heat Gun
the part of the plan you are using with waxed paper Hobby Saw (X-Acto Razor Saw)
so you don't glue the model to the plans! If the parts X-Acto Knife, #11 Blades
do not match the plans exactly, it is because the plans Pliers
have changed size with moisture in the air. Do not Screw Driver
be concerned about this. The parts were all cut to fit 10 ft.-Kite String or Strong Thread
each other. Use the plans as a guide. T-Pins
Straightedge
Remember this: In order for your PT40 to per- Masking Tape
form as it should it is your responsibility to take your Sandpaper, Coarse (100 grit) and fine (220 grit)
time when building and to follow all the instructions Waxed Paper
given. A careful builder will produce a model that is Balsa Filler
straight, true and warp-free. A well built model per-
forms best and will fly like it was designed to. So Note: As with any other hobby, you may go "all
take your time and enjoy! out" if you choose by purchasing all sorts of special
hobby tools and accessories (there are hundreds avail-
If at all possible, get an experienced model buil- able). However, most of the PT40 parts are accurately
der to look at your model during the construction pre-cut so you can build it without a lot of special
process. It is much easier to make corrections at these tools. Some of the more advanced R/C kits require
times. the builder to do a lot more cutting and sanding, so
you may eventually want to equip your workshop
The building instructions follow. If you have with tools like a Dremel Moto Tool, jig saw, small
any questions about building or flying the PT40, table saw, disk/belt sander, small drill press, small
please call us at (217) 398-8970 and we'll be glad to band saw, etc., but these are not necessary now.
help.
It is a good idea to obtain the following items SPECIAL NOTE ON ENGINES
before you start building as you will need to install
or test fit some of them before assembly is complete. Choose the right sized engine for the PT40 as
Most of these items can be purchased from your local indicated here. We recommend a .25 to .40 two cycle
hobby dealer. engine or a .30 to .45 four cycle engine. Too large or
too small an engine can result in an unsafe or poor
ITEMS NEEDED: flying model. Remember that a model engine is not
1- 10 x 6 Propeller or Proper Size for Your En- a "toy" but a device that can cause serious bodily
gine harm to you or others on the ground or cause harm
1- 2-1/4" Spinner or Acorn Type Prop Nut in the air if abused or misused.
2- 2 1/2" or 2-3/4" Main Wheels
1- 2-1/4" or 2-1/2" Nose Wheel
 TYPES OF WOOD

TAPERED
AILERON AND
TRAILING EDGE
STOCK

HARDWARE

#4x5/8 SCREW #2x3/8"SCREW 4-40x1" BOLT 5/32" COLLAR AILERON CLEVIS

#4x1/2" SCREW 6-32x3/16" S C R E W 2 - 5 6 x 3/8" S C R E W AILERON CLEVIS

CONNECTOR

PT40 PARTS
 GET READY TO BUILD D 3. Punch out all the die cut parts excepting the
sheets stamped "A" and "B". If a part does not come
D 1. Unroll the plan sheet. Re- roll it inside out to out easily, cut around it with an X-Acto knife. Mark
make it lie flat. Note: The fuselage plan is printed the die cut parts before punching them out. Also
on Side 1 and the wing plan is printed on Side 2. save any scrap wood until you are completely finished
building. You will use some scrap to build the model.
You will find that scrap wood is quite handy to use
for lots of things, like spreading epoxy for instance.

D 2. As you remove all parts from the box, use a felt D 4. Separate the p a r t s into four groups: 1-
tip pen to write the name or number on each part. FUSELAGE, 2- WING, 3- FIN & STABILIZER, 4-
To identify the parts, compare them with the plans HARDWARE
and with the die-cut parts patterns shown here:
IMPORTANT: READ THIS BEFORE
DIE CUT PARTS PATTERNS STARTING TO BUILD
« The PT40 may be built as a "3-Channel" or
PT40W07 13 PER KIT WING RIBS 3/32x 3x12 BALSA "4-Channel" trainer.
In the 3-channel version, you control the rud-
der, elevator and throttle, and it uses "Wing A" which
has a fixed (non-moving) trailing edge and a large
amount of dihedral. It requires a radio having 3 or
more channels.
WING "A"
MORE DIHEDRAL

PT40F07 I PER KIT 1/8 x 3-7/8 x 12 3/4 PLY

C3
SERVO TRAY

FUSELAGE BOTTOM

PT40FIO 2 PER KIT 1/8 x 3-7/8 x 13-1/2 PLY

LOCKPLATES | J
F-l

\^ STAB SADDLE DOUBLER /

1

PT40F05 I PER KIT 1/8 x 3-7/8 x 9-3/4 PLY PT40W15 1 PER KIT____1/8 x 4-1/4 x 11-1/2 PLY

LESS DIHEDRAL
i

MOVEABLE AILERONS

The 3-Channel version is the easiest to build

and most stable; therefore, if you are a beginner we
strongly recommend that you build your PT40 as a
3-Channel airplane with Wing A.
 The 4-Channel version has more ability to per- D 6. Remove the fuse side from the plan and make
form acrobatic maneuvers, but is more difficult to small marks on the top and bottom edges, where the
build and its self-recovery characteristics are not lines end.
quite as good. If you already have some R/C flying
experience and are ready to move up to an airplane
that is more maneuverable, you may choose to build
your PT40 as a 4-Channel airplane with Wing B.

BUILD THE FUSELAGE SIDES

D 1. Take the two large 1/8" balsa fuselage sides
and put them together. Carefully line them up along D 7. Put the two fuse sides together (inside to in-
the bottom edge and the front. Tape them together side), and line them up carefully. While holding them
with a few pieces of masking tape along the bottom together, transfer the edge marks over to the left fuse
edge to prevent them from moving. Now examine the side edges as shown here.
other edges to make sure the two fuselage sides are
exactly the same all around. If not, use a T-bar sander
with 100 grit sandpaper to lightly sand the edges to
match.

D 8. Now draw lines on the left inside fuse side,

using the edge marks and a straight edge.

D 2. Now, with the tape still in place along the

bottom edge, let the two sides fall open and write
"Rt inside" and "Left inside" as shown here. D 9. Lay the large 1/8" ply fuse doubler on the right
inside fuse side and position it to line up at the nose
and bottom edge. The part of the doubler which is
behind the L.G. plate area must be exactly 1/8"
above the bottom edge of the fuse side. Use a piece
of 1/8" balsa (such as the "windshield" piece) to check
this spacing. When you are satisfied that the doubler
is correctly lined up, apply thin CA glue all around
the edges while holding the doubler in place. Use
enough glue to make sure it flows under the plywood
to make a good bond.

D 3. Tape the fuselage plan to your building sur-

face.
D 4. Lay the right fuse (fuselage) side on the plan,
and carefully position it so the bottom edge and the
nose line up with the plan. Insert a few pins or tape
to hold it in place.
D 5. Using the "locator arrows", a straightedge
and a pen, draw six vertical lines on the fuse side as
shown. Press lightly to avoid damaging the balsa.
D 10. Position the upper and lower "lock plates" and
the stab saddle doublers on the right fuse side, using
the vertical guidelines previously drawn. The upper
lock plates and stab saddle doubler must be even with
the top edge of the fuse side. The three lower
lock plates must be positioned 1/8" above the bot-
tom edge of the fuse side. Use a piece of 1/8" balsa
as a spacer to aid in correct positioning of the bottom
lock plates. Glue these parts in place with thin CA.
(See photo on next page.)
D 11. Notice that the 1/8" balsa fuse side has two
slightly rounded corners at the front of the "hatch" D 15. Use one of the 3/8" ply engine beams as a
area and at the front of the "stab saddle" area. Using spacer to position the 1/4" balsa upper tripler. Move
the upper tripler forward or back until it lines up
an X-Acto knife, cut away these rounded comers to
match the doublers. with the line you drew in Step 13.

D 12. Turn the fuse side over and lay the 1/8" balsa D 16. Remove the 3/8" ply spacer, then glue the upper
upper fuse side in place on the doubler, lining up tripler in place with thin CA all around the edges.
the curved "windshield" edge. Apply glue all around
the edges of this upper fuse side. D 17. Glue the fuselage doubler, upper and lower
lock-plates, upper fuse side, stab saddle doublers and
the 1/4" balsa triplers to the left inside fuselage side.
Be sure to follow the same procedure as set forth in
steps 9-16 when doing so, but don't make two Rt.
fuse sides!
D 18. Drill or cut out the 5/16" holes in the fuse sides
for the wing hold-down dowels. If you use a drill, lay
the fuse side on a wood block for a backing to drill
into, which will prevent the balsa from tearing.
ASSEMBLE THE FUSELAGE
LI 13. Draw a straight line connecting the front edge
of the front slots in the fuse doubler.

D 14. Lay the 1/4" balsa lower tripler in place on

the fuse doubler, and line it up with the line just D 1. Before assembling the fuselage, make sure
drawn and the edge of the doubler Glue the lower that the following parts are set out within easy reach:
tripler in place with thin CA all around the edges. both fuse sides with doublers and triplers securely
glued on; formers F-l through F-6; 1/8" ply fuse bot-
tom; 3/8" ply L.G. (landing gear) plate; 1/8" balsa
fuse bottom; the tapered balsa "fuse tail wedge" and
the six #62 rubber bands provided.
 Note: In the next steps you will assemble the
fuselage without glue! The interlocking parts ena-
ble you to do this so you can get everything together,
make sure the parts fit properly, check for straight-
ness and make adjustments if necessary. Then you
will glue everything together by applying thin CA.
D 2. Make the "firewall" (Former F-l) by gluing
together the two 1/8" plywood parts which are marked
"F-l". Use 5 minute epoxy for this job. After the epoxy
has hardened, drill four 1/8" holes at the marks for
the nose gear bearing mounting holes.
D 3. Lay the right fuse side flat on the work surface. D 8. Put F-5 and F- 6 in place in the lock-plate
Insert formers F-l and F-2 into their respective slots notches and secure with rubber bands.
in the right fuse side doubler. D 9. Note that the rear end of the stab saddle doub-
lers touch, preventing the rear ends of the fuse sides
from coming together. Using your T-bar, sand the
rear portions of both the stab saddle doublers as
shown until the rear ends of the fuse sides nearly
touch.

D 4. While holding F-l and F-2 upright, lay the left D 10. Turn the fuselage upside down and place the
fuse side in place on these formers. Now put the 1/8" 3/8" ply L.G. plate into the slots provided. Secure
ply fuse bottom in place in the slots provided. with masking tape.
D 11. Now take the 1/8" balsa fuse bottom and care-
fully slide it in place, narrow end first, under the
rubber bands, starting at F-3.

D 5. Holding these five parts together with one

hand, slide two #62 rubber bands over the nose, leav-
ing one around F-l and one around F-2. D 12. Finally, insert the tapered balsa fuse tail
wedge, and secure with a small rubber band or mask-
Note: Notice that the fuselage has now become ing tape.
somewhat rigid and square. Before proceeding make
sure that the tabs in F-l, F-2 and the fuse bottom are
properly inserted into the slots in the fuse doublers.
Position the fuselage in its normal (upright) position
while inserting the other formers in the next steps.
D 6. Put former F- 3 in place and secure by sliding
a rubber band around the fuselage from the rear.
D 13. Temporarily install the 3/8" ply engine beams
D 7. Slide another rubber band around the fuse to and the 1/4" ply breakaway plates. Hold in place with
the F-4 location, pulling the fuse sides together. Now masking tape. Now position your engine on the
work F-4 into place in the lock-plate notches. breakaway plates and your fuel tank behind F-l.
Don't worry about exact fits at this time. While hold-
(See photo at top of next column.) ing these parts in position, determine where to drill
the holes in F-l for the fuel lines and the throttle
pushrod. (See photo and notes on next page.)
 NOTE ON ENGINES: The engine mount D 18. Check your assembly of the fuselage, making
"breakaway plates" have been cut to an average width sure that all former tabs are in their respective
which will permit mounting almost any engine you notches and all parts are in place. Set the fuselage
choose. However, you may have to trim these plates assembly on the plan top view. Your fuse assembly
slightly to fit your engine. The best way to do this is should line up with the plan within 1/16". If not,
to sand or file away a little at a time from the inside something is wrong and you should try to straighten
edges of both breakaway plates until your engine fits it out. If the alignment is far off and you can't find
between the plates. the problem, consult with an experienced model buil-
der to correct the problem before proceeding.
D 19. Lay down a 50" long piece of waxed paper to
protect your building surface. Set the fuselage assem-
bly upright (in its normal position) on the waxed
paper. With everything in its proper place, apply thin
CA glue to all the joints, around the formers and
along the bottom. Wait a minute for the glue to set,
then apply thick CA to the joints to make sure a
good bond exists, especially in the joints that do not
fit perfectly. Note: The use of "Zip Kicker" or other
CA glue accelerator will be helpful when using thick
CA to fill any large gaps.
NOTE ON FUEL TANK: The PT40 requires D 20. Remove the rubber bands from the fuselage.
any 6 or 8 oz. fuel tank of your choice. Most tanks In the above step you may have glued the rubber
have three possible openings, one for fuel pick- up, bands to the wood in some places. If so, just cut the
and two for the fill/vent lines. We recommend that rubber away from the wood with an X-Acto knife.
you only use two lines. Run one line from the "klunk"
pick-up to the fuel fitting on the engine carburetor INSTALL THE WINDSHIELD
and the other to the "pressure tap" fitting on the AND HATCH
muffler. D 1. Put the 1/2" balsa triangle windshield brace
D 14. Because you have not yet glued the fuse parts in place and apply thin CA glue.
together, you may now carefully remove F-l and drill
the holes for the fuel lines and throttle pushrod.
D 15. Insert four 4-40 blind nuts part-way into the
1/8" holes previously drilled. Insert them from the
back side of F-l. Apply one drop of thick CA glue
under the wide part of each nut, then immediately
press them firmly in place with a pliers or a vise.

4-40 BLIND NUT

D 16. Replace F-l back into the fuse. D 2. Sand the 1/2" balsa triangle to match the curve
on the fuse sides.
D 17. By now you should have decided which wing
you are going to build, "Wing A" (without ailerons),
or "Wing B" (with ailerons). If you have chosen'
"Wing A", find the four F-2A wing saddles and put
them into the slots behind F-2 and in front of F-3. If
you have chosen "Wing B", use the F-2B saddles.

D 3. Sand the bottom edge of the l/8"balsa

windshield at an angle so it will rest flat on the fuse
sides.
D 4. Apply thick CA to the 1/2" balsa triangle, then
immediately place the windshield in position, hold-
ing the bottom against the triangle.
10 (See photo, top of next page.)
D 5. Wet the top surface of the windshield so the
wood will bend without breaking.
D 6. Apply thick CA to the top of F-2 and the fuse
sides where the windshield will contact, then im- MOUNT THE ENGINE BEAMS AND
mediately bend the windshield down and hold until BREAKAWAY PLATES
the glue sets
D 1. Glue the 3/8" ply engine beams in place using
5 minute epoxy. With a tissue, wipe off any excess
epoxy that squeezes out when sliding the beams into
the slots. Allow the epoxy to fully cure before disturb-
ing the beams.

D 7. Trim any excess windshield even with the back

edge of F-2.
D 8. Taper the rear edge of the 1/8" ply hatch to fit
the windshield as shown on the fuse plan side view.
D 9. Find the piece of 1/8" ply that you punched D 2. Holding the 1/4" breakaway plate under the
out of F-5. This is used as the hatch tongue. Glue the 3/8" ply beam, draw a line on the breakaway plate
hatch tongue to the bottom of the 1/8" ply hatch with to mark the edge of the beam.
thick CA. Let the hatch tongue extend about 1/2"
beyond the back edge of the hatch.

D 3. Now place the breakaway plate on top of the

beam and while holding the plate firmly in place,
D 10. Draw a guideline 1/8" back from the front edge drill three 3/32" holes as shown, drilling down
of the hatch. This is the centerline of the three hatch through the breakaway plate and the beam. Do this
hold down screws. for both plates and beams.

D 11. Holding the hatch firmly in position, drill three

1/16" holes along the guideline •
D 12. Remove the hatch and re-drill the holes in the
hatch only to 3/32". Then attach the hatch to the fuse
with three #2 x 3/8" screws. (See photo, top of next
column.)

11
D 4. Remove the breakaway plates and re-drill the
holes in the breakaway plates only to 1/8".
D 5, Fasten the breakaway plates to the beams
using six #4 x 5/8" screws.

PREPARE THE NOSE GEAR

D 1. Referring to the steering arm drawing here,
cut off about 3/16" of the steering arm so it will clear
the fuse triplers. Drill out the end hole to 5/64"diame-
ter for pushrod wire clearance.
TRIM 3/16" HERE

D 2.Assemble the nose gear steering arm which

#4x5/8" SCREW consists of a nylon arm, a 5/32" wheel collar and a
6-32 x 3/16" screw.
INSTALL THE LANDING GEAR
D 1. Turn the fuselage upside down and position
the 5/32" wire main L.G. (landing gear) on the ply
L.G. plate. Set the four nylon L.G. straps in place
and mark the location for the eight screw holes. Drill
3/32" (or slightly smaller) holes at the marks.____

D 3. Place the steering arm assembly into the nose

gear bracket making sure that the wheel collar open-
ing on the steering arm is down and the screw is
facing out.
11

D 2. Temporarily mount the main LG using the

nylon straps and the #4 x 1/2" screws.

#4x1/2" S C R E W 4-40x1" BOLT

D 4. Referring to the nose gear diagram on the plans,
D 3. Temporarily mount the nylon nose gear bearing slide the nose gear wire through the holes in the
using four 4-40 x 1" bolts screwed into the 4-40 blind nose gear bearing and wheel collar/steering arm.
nuts previously installed. Tighten the screw, making sure the steering arm is
at the angle shown on the top view of the fuselage.

D 4. If you are a young person, you should ask CUT THE NOSEGEAR PUSHROD
an adult to help you with the following step: OPENING
Using a side cutter, cut off the excess bolt length
D 1. Mark and drill a 1/8" hole through Former F-l
sticking out behind F-l. You must wear eye protec-
in the position shown on the F-l drawing on the plan.
tion when doing this! Note: An alternate method
This hole is for pushrod clearance.
is to mark the bolts with an indelible marker, remove
them from F-l, and cut them off at the marks with See photo, top of next page
a side cutter, hacksaw or a Dremel cut-off wheel.
(See photo, top of next column.) 12
 D 3. Find the two 1/4" x 1/4" x 5-7/8" balsa pieces.
These are used for the ends of the stab and elevator.
Cut a 1-3/8" length from each of these pieces and
glue them to the ends of the elevator using thin CA
glue. Sand the ends even with the elevator using a
sanding block.
D 4. Take the two remaining pieces of 1/4" x 1/4"
balsa and glue them to the ends of the stab and sand
to blend in.
CUT THE PUSHROD EXIT SLOTS FOR
THE RUDDER AND ELEVATOR D 5. Round the corners of the fin, rudder, stab and
elevator as shown on the plan.

D 1. Find the location of the "Pushrod Exits" on

the fuselage plan (side view). Measure their locations
in relation to the fuse bottom and the back of F-6,
and transfer these measurements to your fuselage.
Note that the pushrod exit shown in dashed lines is
for the rudder pushrod exit on the left fuselage side.

D 6. Sand the fin and stab smooth with a T-bar

sanding block and 100 grit sandpaper.
D 7. Put the elevator and stab together and sand
D 2. Cut out the slots with an X-Acto knife. the tips to the same length.

This completes the fuselage construction for D 8. Using a sanding block, sand the following to
now. Note that you have not yet installed the top a rounded shape: stab leading edge (excepting the
sheet. Set the fuselage assembly aside. flat center portion), stab tips, elevator trailing edge
and tips, fin leading edge, fin tip, rudder trailing
BUILD AND INSTALL THE "TAIL edge and rudder tip.
FEATHERS"
D 9. Using a fine point felt tip marker, carefully
Q 1. Working on waxed paper on a flat surface, glue draw a centerlirie all along the stab trailing edge,
the 1/4" balsa fin front to the 1/4" balsa fin rear elevator leading edge, fin trailing edge and rudder
using thin CA. Immediately wipe off any excess glue leading edge.
to make sanding easier. Apply glue to both sides of
the joint.

D 10. Using a T- bar sanding block with 100 grit

sandpaper, sand the elevator leading edge and rudder
leading edge to a "V" shape. Work slowly and care-
D 2. In the same manner, glue the stab (stabilizer) fully so you don't sand away too much balsa. When
front to the stab rear. you have finished, the centerlines you previously
drew should remain, and the "V" shape should look
like the sketch shown above the fin on the plan.

13
 MAKE THE HINGES
D 1. Take the 9" strip of hinge material and roughen
both sides with 220 grit sandpaper. This is best done
with a small piece of sandpaper held with your fin-
gers, rather than a sanding block. Do not sand the
centerline of the hinge material.
D 2. While holding the elevator in place against
the stab trailing edge, transfer the hinge locations
to the elevator leading edge.

D 2. Using a ruler and a ball point pen, draw lines

dividing the hinge material into eighteen 1/2" -wide
segments.

D 3. Repeat the above process marking the hinge

locations on the fin and rudder. Don't forget to mark
the bottom hinge location on the rudder.
CUT THE HINGE SLOTS
D 1. Move the fin trailing edge close to the table
D 3. Drill four 1/16" holes in each of the hinge seg- edge. Place a small piece of 1/8" plywood (from die-cut-
ments as shown on the plan. Use a wood block as a ting scraps) next to the hinge slot location.
backing to drill into when drilling these holes.
D 2. Hold your X-Acto knife straight on the scrap
wood and cut straight into the fin. The slots should
be about 1/2" deep (enough for half of the hinge to
fit into).

D 4. Fold the hinge material back and forth a few

times on the centerline to "condition" the hinges.
D 5. Cut the hinges apart with a scissors on the
lines you previously drew. Also snip off a small piece
D 3. Trial fit by pushing the hinges (no glue) into
of each hinge comer.
the slots to make sure you have cut the slots wide
enough and deep enough.
D 4. Repeat this process for the rudder, elevator
and stab.
MOUNT THE STAB ON THE FUSE
D 1. Remove the nylon nose gear bearing and the
main gear from the fuselage.

D 2. Lay the stab on the plan and carefully line it

up with the outside lines. While holding it in this
Note: You should end up with 18 hinges, 8 of position, lay a straight edge along the "fuselage cen-
which you will use for the ailerons if you are building terline" as shown on the plan. Draw the fuselage
the "B" wing. centerline on the top of the stab with a fine point
marker. Work as carefully as you can when doing this!

MARK THE HINGE LOCATIONS (See photo, top of next page)

D 1. Lay the stab on the plan and mark the hinge

locations on the stab trailing edge (both sides are
the same).

14
 the stab slightly until both measurements are the
same within 1/16" .

D 3. With the fuse on a flat surface, lay the stab

in place on the fuselage in the stab saddle area with
the front of the stab touching the rear surface of F-6
and centered side-to-side.
D 4. While holding the stab firmly in place onto
the saddle, measure down to the flat work surface
from both ends of the stab. If one side is higher than E- When you finally have the stab accurately
the other, sand the high side of the stab saddle with aligned on the fuse, make four little "alignment
your T-bar sanding block and 80 or 100 grit marks" on the stab where the leading and trailing
sandpaper. Replace the stab in the saddle and re- edge of the stab intersect with the outside edges of
check the measurements. Continue this process until the fuse sides. You will use these marks to quickly
the stab is level within 1/16". and accurately position the stab when gluing it in
place. Now remove the stab.
F- Mix up a batch of epoxy and spread it on the
stab saddle and the back of F-6. Lay the stab in place
using the "alignment marks" for positioning. Before
the glue sets, re-check the measurements in step D.
Hold or pin the stab in place until the glue sets.
MOUNT THE FIN TO THE STAB
Note: Probably the single most troublesome
cause of poor flying models is improper fin alignment.
NOTE: READ THROUGH AND PRAC- Therefore, you should take the time and care neces-
TICE THE NEXT 6 STEPS (A-F) BEFORE PRO- sary to do your "best when performing this next set
CEEDING. of steps. Read through the next five steps before
beginning!
D 5. Now glue the stab securely to the stab saddle
with 5 minute epoxy. (You may perform this step with D 1. At the front and back of the "fuse centerline"
5 minute epoxy, but a slower curing epoxy will give which you previously drew on the top of the stab,
you more time to make sure the alignment is correct.) make accurate marks 1/8" right and left.
It is important that the stab be centered and square
on the fuselage; so, follow this procedure exactly:
A- With a ruler, measure to find the exact center
of the top of F-3. Stick a pin in at this point.

D 2. Using a straight edge and a fine point marker,

connect these marks, making two parallel lines, one
on each side of the fuse centerline.

B- Also measure to find the center of the top

of F-6 and mark this point with a pencil.
C- Lay the stab in the saddle and line up the
"fuse centerline" (which you previously drew on top
of the stab) with the mark on F-6 and with the center
joint at the rear of the fuse.
D- Check the "squareness" of the stab by
measuring from the rear corners of both stab tips to
the pin in the center of F-3. Adjust the position of 15
D 3. With the rudder attached to the fin by the top
three hinges (not glued in), trial fit the fin onto the
fuse. If the rudder is too long and touches the flat
work surface preventing the fin from resting on the
stab, sand a small amount off the bottom of the rudder.

D 8. Now temporarily assemble the elevator to

the stab and the rudder to the fin. Swing the rudder
from side to side and the elevator up and down. The
rudder and elevator must not touch in any pos-
ition! If they do, carve or sand the notch in the rudder
to insure that they will not bind. In addition, make
sure no part of the fin interferes with the free upward
movement of the elevator.

D 4. Apply 5 minute epoxy to the bottom of the fin

and position the fin between the guidelines you pre-
viously drew. Slide the fin/rudder assembly forward
until the bottom of the rudder just touches the back
of the fuse. Wipe away any excess epoxy with a tissue.
Lay the fuselage assembly aside for now.
D 5. Before the epoxy sets, check the squareness
of the fin with the stab, using a small carpenter's CHARGE YOUR NICAD BATTERIES
square or draftsman triangle. Hold position until the epoxy sets firmly.
D 1. Read the instruction manual for your radio
system to become familiar with how to hook it up.
D 2. Charge your transmitter and receiver bat-
teries now so they will be ready when you need them.
Note: Charge the batteries for the time recom-
mended for the first charge...usually 18-24 hours.
BUILD THE WING PANELS
NOTE: Like the fuselage, the PT40 wing is
made to fit together without glue, so you can assem-
ble all of the major parts and check to make sure
D 6. Find the two 4-7/8" lengths of l/4"balsa triangle
they are all lined up before applying thin CA to the
and sand the ends to a rounded (or pointed) shape
joints.Thick CA will be added after the thin CA has cured.
as shown on the plan. Trial fit these pieces in place
at the fin/stab joint. Later, when you are covering D 1. Turn the plan over to side 2, which shows the
the model (and before you cover the fin and stab) wing. Tape or pin the plan to your flat work surface
cover the outer surface of these triangular pieces, so the "Right Wing Panel" is facing you. Cover the
leaving about l/8"of excess covering all around the right wing panel drawing with waxed paper (so you
edges. Then glue these pieces in place and iron down won't glue the wing to the plan!).
the excess covering to the fin and stab
D 2. The shaped and notched wing leading edge
(L.E.) and trailing edge (T.E.) are fastened together
by a thin layer of balsa. Separate them by folding
until the balsa breaks. Sand away the excess balsa
that remains along the edges after breaking them
apart, using a T-bar with 100 grit sandpaper.

D 7. You previously marked the four hinge loca-

tions on the rudder. Now transfer the bottom hinge
location over to the rear of the fuse. Cut the hinge
slot in the tapered balsa fuse tail filler.
(See photo, top of next column.) 16
D 3. Before using the L.E. and T.E. pieces, you must D 6. Insert the fronts of the ribs into the notches
determine which pieces are to be used for the right in the balsa leading edge (L.E.).
wing panel. Here's how:
D 7. Insert the backs of the ribs into the notches
A- We have drawn red lines on the top of each in the balsa trailing edge (T.E.).
piece.
D 8. Adjust the position of the leading edge and
B - Notice that the pieces are notched on one trailing edge left or right so they match the plan at
end, but not on the other. The notched end goes toward the right tip. Tape or pin them to the plan so they
the wing tip, and the end without a notch goes toward don't move.
the center of the wing.
C- Take one of the L.E. pieces and lay it on the
right wing panel plan with the red line up. If the
notched end is on the right side (at the tip) you have
the correct L E.

D 9. The tip rib should now match the plan exactly.

However, due to shrinkage or expansion of the paper,
the other ribs may not line up perfectly. That is OK,
because the notches in the L.E. and TE. are cut in
D- Do the same thing to determine which T.E. the right places. Before proceeding, make sure none
piece to use. of the ribs are bowed (curved). If they are, straighten
them by sliding the center part right or left on the
D 4 Tape one of the 3/8" x 1/2" basswood spars to spar.
the plan, with the right end of the spar lined up with
the tip. The excess spar length must extend past the D 10. Insert the top 3/8" x 1/2" spar into the top
wing centerline.Apply tape in 3 places, between the notches in the ribs, so the right end is even with the
ribs, near the ends and in the middle. tip rib.
D 11. Insert two of the 3/16" x 3/16" basswood spars
into the small notches in the top of the ribs, so the
right ends are even with the tip rib.

D 5. Remove the 3/32" balsa wing ribs from the die

cut sheets and slide 12 ribs into place on the bottom
spar, using the plan to get them close to their proper
position DO NOT PUT A RIB AT THE CENTER-
LINE.

D 12. Make sure that the ribs are all down onto the
plan and fully inserted into the notches in the L.E.
and T.E.

17
D 13. Apply thin Ca to all joints. After the thin CA Clamp or hold the parts until the glue hardens.
has cured, apply some thick CA to each joint.
Set the right wing panel aside, and turn the
D 14. Find the die-cut plywood sheets containing the
Dihedral Braces, Wing Braces, F-2's and Gauges plan around so the left wing panel is facing you.
(PT40W14 & PT40W15). If you are building wing "A" D 18. Build the left wing panel in the same manner
(without ailerons), punch out all the parts that apply to the as you did the right panel, following steps 1 through
"A" wing. Compare each part with the drawings on page
6 and mark them with their correct letter and number (A- 16.
1, A-2, etc.). If you are building the "B" wing, use only JOIN THE WING PANELS
the parts with a "B" on them.
D 1. Lay the left wing panel flat on the building
D 15. Using the "dihedral gauge" (A or B, depending surface or a large flat table. Place a sheet of waxed
on your wing choice), draw cut-off lines on the back paper under the "center" portion of the panel where
of the L.E. and the front and back of the spars and it will be joined to the right half.
T.E. (See the sketch on the plan showing how to do
this.) The point of the dihedral gauge must be D 2. Slide the right wing panel into position, so
exactly on the centerline when marking the cut- the spars touch the spars of the left panel. Block up
off lines. the right tip with a stack of books The stack of books
must be 8" high for wing A and 5" high for wing B.

D 16. Using a razor saw (or any fine-toothed saw),

carefully cut off the L.E., spars and T.E. on the lines
you just drew.

D 3. Check to make sure the L.E., spars and T.E.

are touching. If not, sand off any long ones slightly
until they all touch. Now slide the panels apart.
NOTE: PRACTICE THE NEXT STEP
"DRY" BEFORE ACTUALLY DOING IT!
D 4. Mix up a batch of epoxy (30 minute epoxy is
D 17. Using 5 minute epoxy: preferred here to give you more time, or 5 minute
epoxy may be used if you work quickly), and apply
it to the dihedral braces, L.E., spars and T.E. Slide
the panels together and wipe up the excess glue with
a tissue.

Glue A-l or B-l to the back of the leading edge.

Glue A-2 or B-2 to the front of the main spars.
Glue A-2 or B-2 to the back of the main spars. Make sure the wing panels remain in posi-
tion until the epoxy has fully hardened.
Glue A-3 or B-3 to the front of the trailing edge.
Remove any excess glue with a tissue.
18
NOTE: Skip to page 39 and add the
shear webs as described on that page.
 INSTALL THE CENTER RIBS AND D 6. Working on waxed paper, glue the bottom
BOTTOM SHEETING sheeting to the inside edges of the ribs and dihedral
braces.
LI 1. After building the wing, you have two ribs
remaining. Lay these ribs, one at a time, on the draw- D 7. Turn the wing upside down and inspect the
ing in the lower left comer of the wing plan. With a bottom of the center section. If there are any major
straight edge and a pen, mark the four cut-off lines, gaps between parts, fill them with balsa dust (from
using the arrows as a guide. sanding) and apply thin CA.
D 8. Sand the bottom of the center section smooth
with a sanding block and 100 grit sandpaper.
At this point the bottom center section should
look like this:

D 2. Cut the ribs at the cut-off lines using a razor

saw.
D 3. Place the two "front parts" together and the
two "aft parts" together, and apply thin CA glue
around the edges.

INSTALL TAPERED TRAILING EDGE

(WING A ONLY)
Note: The following 7 steps apply only to wing
A (without ailerons). If you are building Wing B, skip
D 4. Position these center rib parts in place in the to the next section now.
center of the wing and glue them to the L.E..spars
and T.E. You may use thin CA if the ribs fit perfectly; D 1. Find the two tapered balsa T.E. pieces. They
otherwise use thick CA or epoxy. are 1-3/16" wide and 30" long.
D 2. Place one of the trailing edge pieces against
the rear edge of the right wing panel on a flat surface.
If there is a 3/32" gap along the top edge, that means
the T.E. is upside down If so, turn it over.

D 5. From the sheet of 1/8" x 3" x 13" balsa, cut

rectangles to fit between the center rib and the 2nd
rib in both wing panels The easiest way to do this
is to lay the wing right on the 1/8" balsa sheet and
trace around the inside edge of the ribs and spars as D 3. Working on a flat surface covered with waxed
shown here. paper, hold the tapered T.E. firmly against the rear
edge of the Rt. wing panel with the left edge at the
wing centerline, and apply thin CA along the joint.
Make sure the wing and the T.E. are down flat on
the work surface when doing so.
D 4. Take the other tapered T.E. and determine
which side goes up, as in step 2.
D 5. Trial fit this piece in place against the rear
edge of the Left wing panel. You will probably notice
that there is a gap on the bottom, where the two T.E.
Note: The grain of this bottom sheeting must pieces come together. If so, sand the end of the T.E.
run in the same direction as the spars. so it fits snugly against the end of the right T.E.
D 6. Glue the left tapered T.E. in place, as in step 3.
19
D 7. With a razor saw, cut off the ends of the tapered
trailing edges even with the tip ribs.

There are several ways to accomplish this, so

you may choose one of these:
A- File the groove with an 1/8" or 5/32" diameter
round file, available at hardware stores (this type
of file is normally used to sharpen small chain saw
INSTALL TRAILING EDGE, AILERONS teeth).
AND TORQUE RODS (WING B ONLY)
B- Cut the groove with a 5/32" outside diameter
Note: The following 27 steps apply to wing B brass tube. You can sharpen the tube by cutting
(with ailerons). If you are building wing A, skip to around the inside of one end with an X-Acto knife.
the next section now.
C- Cut the groove by running the T.E. piece
D 1. Find the two tapered balsa T.E. (trailing edge) over a small table saw, with the blade set at the
pieces. They are 1-3/16" wide and 30" long. height needed to cut a groove 5/32" deep.

D 2. Place one of the T.E. pieces against the rear D- Rout the groove out with a Dremel Moto
edge of the right wing panel on a flat surface. If there Tool and a 1/8" bit.
is a 3/32" gap along the top edge, that means the T.E.
D 7. Turn the two inboard T.E. pieces upside down
is upside down. If so, turn it over.
as shown in the following photo, and measure 7/16"
D 3. Just below the right wing drawing (on the out from the "wing centerline". At the 7/16" point,
plan), there is a separate drawing showing the aileron cut a notch in both pieces with an X-Acto knife, pro-
details. Using this drawing as a guide, cut the tapered viding free movement for the threaded portion of the
T.E. into three parts. Label these parts: "Rt. inboard aileron torque rods.
T.E.", "Rt. Aileron" and "Rt. outboard T.E."
("Rt." is an abbreviation for "right".)

D 8. Roughen the surface of the nylon torque rod

bearings using a piece of 100 grit sandpaper.
D 4. Glue the Rt. outboard T.E. piece to the rear D 9. Slide the nylon torque rod bearings as far as
edge of the right wing panel. The outer edge of the they will go toward the threaded portion of the torque
T.E should be even with the tip as shown on the plan. rods.
D 10. With a toothpick, apply a small amount of
petroleum jelly (Vaseline, etc.) around the torque rod
where it enters the nylon bearing. This will help
prevent any excess glue from getting in and possibly
"locking up" the torque rod.
D 11. Place the torque rods into the grooved T.E.
pieces.
D 5. Repeat steps 1-4 for the left side, making the
"Lt. inboard T.E.", "Lt. Aileron" and "Lt. outboard
T.E." ("Lt." is an abbreviation for "left".) STOP! AT THIS POINT YOU MUST CARE-
FULLY STUDY THE PLANS AND PHOTOS TO
D 6. Find the "aileron torque rods". You will MAKE SURE YOU HAVE THE RIGHT TORQUE
notice that there is a black nylon tube on each of the ROD IN THE RT. INBOARD T.E., AND THE
bent rods. This nylon tube is called the "torque rod LEFT TORQUE ROD IN THE LT. INBOARD T.E.
bearing". You must now make a groove in the front THE THREADED PORTION MUST COME OUT
edge of each inboard T.E., so the torque rod bearing THE BOTTOM, AND THE SHORT BENT END
may fit into the groove. MUST POINT TOWARD THE REAR.

20
D 12. If the nylon bearing fits snugly into the groove, D 19. Sand the leading edge of the ailerons to a "V"
you may use a few drops of thin CA to glue it in place. shape as shown on the plan.
If you have a loose fit, use thick CA or epoxy. DO D 20. Groove the leading edge of each aileron to
NOT GET GLUE INTO THE ENDS OF THE accept the torque rods.
NYLON BEARING TUBE!
D 21. Trial fit the ailerons onto the torque rods.
D 13. Turn the wing upside down, with the trailing
edge facing you, and temporarily position the inboard D 22. Cut or sand a small amount off both ends of
T.E. pieces against the back edge of the wing. You the ailerons to provide about 1/16" to 3/32" of clear-
will notice the gap between the pieces, caused by the ance at each end. (Remember....the ailerons will be
dihedral angle. Sand the ends of the inboard T.E. covered with Super Monokote or other covering mat-
pieces so they come together without a gap. erial; therefore you must make some space at the
aileron ends so they don't tighten up after covering.)

D 14. With the T.E. pieces taped in their proper pos-

ition mark the location of the slots (where the
D 23. Remove the ailerons and draw a centerline
threaded portion comes out) on the back edge of the
down the back edge of the wing, in the aileron open-
wing as shown. Then remove the T.E. pieces and cut ing.
slots in the back edge of the wing.
D 24. Place the ailerons on the wing plan and mark
the locations of the hinges on the leading edge of the
ailerons. Now put the ailerons back in place on the
wing and transfer the hinge location marks to the
back edge of the wing.
D 25. Cut the hinge slots for the ailerons in the
same way that you did for the elevator and rudder.

D 15. Glue the inboard T.E. pieces to the back of the

wing by carefully holding or taping the pieces in
place and applying thin CA in small drops along the
joints. Use care to avoid getting glue inside the nylon
bearings. D 26. Using 100 grit sandpaper, roughen the ends
D 16. Mark a centerline all the way down the leading of the torque rods that will go into the ailerons.
edge of each aileron. D 27. Trial fit the ailerons on the wing with the
D 17. Hold the ailerons in place against the back hinges in place. DO NOT GLUE THE HINGES IN
edge of the wing and mark the location where the UNTIL AFTER COVERING.
torque rods will enter the ailerons. THE FOLLOWING INSTRUCTION
PHOTOS SHOW THE "B" WING (WITH
AILERONS), BUT THE PRINCIPLES APPLY
TO BOTH "A" AND "B" WINGS.
INSTALL THE WING TIPS
D 1. Sand the wing tips smooth and flat with your
T-bar and 100 grit sandpaper.
D 18. Drill a 3/32" hole in each aileron to accept the
torque rods. D 2. Find the two tapered balsa pieces that are
11-3/8" long. These are the wing tips.
D 3. Holding the wing and wing tip on a flat surface
covered with waxed paper (the narrow edge of the
tapered piece goes down), apply thin CA glue to the
joint.
(See photo, top of next page.)
21
 D 5. Apply thin CA glue around the edges, holding
the plates firmly in place until the glue sets.
TRIAL FIT THE WING IN THE SADDLE
D 1. Using your T-bar sander, sand the inside edge
of the plywood fuse side doublers at the same angle
as the F-2A or F-2B formers.

D 4. Carve and sand the wing tip to blend in with

the tip rib, L.E. and T.E.

D 2. Lay the wing in place on the fuselage with

the T.E. resting against the front of F-3.
D 3. Notice that the center of the wing L.E. rests
on the top rear portion of the windshield, preventing
D 5. Sand the front and rear comers to a rounded the wing from resting down onto the fuse sides. Mark
shape as shown on the plan. Also sand the top and the area of the windshield that needs to be cut away.
bottom edges to a slightly rounded shape.
SAND THE WING SMOOTH
D 1. Lightly sand the entire wing with your T-bar
and 100 grit sandpaper. Pay special attention to
blending the ribs in with the leading and trailing
edges and spars and removing any excess glue re-
sidue that would cause bumps when the covering is
applied later.
D 2. Now lightly sand the wing again with a T-
bar and 220 grit sandpaper. After this step, the wing D 4. Using an X-Acto knife and a sanding block,
should be very smooth and ready for covering. carefully remove part of the windshield, a little at
a time, until the wing rests down flat on the fuse
INSTALL THE WING PLATES sides. You may have to cut into F-2 slightly.
D 1. Find the two pieces of 1/32" x 3/4" x 1-1/2"
plywood. These are the "Wing Plates" which protect
the trailing edge at the points where the wing hold
down rubber bands are fastened.
D 2. Working on the table edge, use a sanding block
to "feather" (taper) the edges of the wing plates.
Feather three edges of each plate, leaving one long
edge square.
D 3. Make marks on the T.E., 1" each way from the
wing centerline. D 5. Find the two 5/16" diameter hardwood wing
hold down dowels that are 5-3/16" long. Round the
D 4. Put the wing plates in position on the T.E. ends of these dowels slightly with sandpaper.
The edge of the plate that is not feathered goes to
the rear along the trailing edge. The 1" marks you D 6. Insert the dowels into the holes in the fuse
made in step 3 are where the plates begin. sides. Enlarge the holes with a round file or drill, if
necessary.
DO NOT GLUE THE DOWELS IN PLACE
UNTIL AFTER THE FUSELAGE HAS BEEN
COVERED.

22
D 7. Attach the wing to the fuselage with eight D 4. Remove the muffler and again put the engine
#64 rubber bands. The bands should all be passing in place on the breakaway plates. This time, however,
over the plywood wing plates on the trailing edge , you must carefully position the engine so it is point-
and the wing should be resting firmly down on the ing straight ahead. Also, the engine must be far
fuselage sides. enough forward to allow the propeller to turn freely
without touching the front of the fuse sides.
D 5. Holding the engine in this position, use a pen-
cil to mark the location of the engine mounting holes
on the breakaway plates. Note: For this step, it is
helpful to have a "mechanical pencil" with the lead
extended, which enables you to mark straight down
through the engine mounting holes.

D 8. With the wing attached to the fuse, and the

fuse bottom resting on a flat surface, measure from
both wing tips down to the flat surface. If the mea-
surements differ by more than 1/8" , sand the wing
saddle area (a little at a time!) until the two measure-
ments are nearly the same.
MOUNT THE ENGINE
D 6. Drill 1/8" holes through the breakaway plates
Note: There are many different engines that at the marked locations.
will be OK for mounting in the PT40 and the engine
mounting system that is used makes it possible for
you to install any engine you choose as long as it is
within the following range: .25-.40 2-cycle, or .35-.45
4-cycle. The following photos show installation of the
O.S. Max .40 FP engine. The plans also have draw-
ings of the K&B .40 (2-cycle) and the O.S. Max .40
FS (4-cycle). Depending on your engine, you may have
to use a slightly different method to end up with a
good solid mount. If you have any trouble, be sure to
ask an experienced model builder for assistance.
D 7. Install 4-40 blind nuts in the bottom of the
D 1. You should already have the breakaway plates
holes you just drilled, as follows:
screwed (but not glued) to the engine beams. The
breakaway plates have also been cut out so your en-
gine can fit down between them. If not, do so now.
D 2. Put the engine in place on the breakaway
plates. Mark the area of the fuse side that must be
cut away to clear the needle valve. Cut this area away
now, using a round file, Dremel Moto Tool or a small
saw.

A-Push the blind nut in part way with your

finger.
B- Apply a drop of thick CA around the base
D 3. Now install the muffler onto the engine, put of the nut.
the engine in place on the breakaway plates, mark C- Immediately squeeze the nut in, using a
and cut away enough of the fuse side to provide clear- pliers or a vise.
ance for the muffler.
23
D 8. Screw the breakaway plates down tightly to vos without first checking to determine which direc-
the engine beams, and notice two things... tion the servos rotate. After the installation has been
completed , the modeler merely flips the switches on
A-Looking at the bottom, do the blind nuts ex-
the transmitter to make the servos rotate in the de-
tend into and between the breakaway plate and the
sired direction. Many of the older systems, however,
engine beam?
do not have servo reversing...instead they include one
B-Do the blind nuts stick out into the area or two "reverse" or "left-handed" servos which rotate
where the engine goes, preventing the engine from in a direction opposite that of the other servos. When
being lowered into place? installing the servos from a system that does not
have servo reversing, you must plan ahead to use
the "reverse" servos where they are needed.
D 1. Prepare the servos (3 are required if you built
Wing A, 4 if you built Wing B) by installing the four
rubber grommets into each servo, then inserting the
brass eyelets up into the grommets.
D 2. Place the servos in the 1/8" plywood servo tray
provided, and space them out so they are not touching
each other or the sides of the opening.

D 9. If your answer to A is yes, remove the breaka- D 3. Holding the servos in place, use a pencil to
way plates and carefully cut away the top layer of mark down through the brass eyelets onto the
plywood on the engine beam, in the area where the plywood. Remove the servos and drill 1/16" holes at
blind nut was hitting. each of the marks.

D 10. If your answer to B is yes, use a flat file to file D 4. Insert the switch into the slot provided in the
away the portion of the blind nut that is sticking out servo tray and mark the locations of the screw holes.
into the engine area. Drill 3/32" holes for the switch mounting screws. Re-
install the switch. Note: Install the switch such that
D 11. Now re-install the breakaway plates. Then sliding the switch toward the right fuselage side
mount the engine to the breakaway plates with the turns the radio off.
four 4-40 bolts provided. Note: Later when you install
the engine the final time (before flying), make sure
you slip the small lockwashers on the 4-40 bolts
before mounting the engine.

D 5. Place the plywood servo tray into the fuselage

to rest on top of the lower portion of the plywood fuse
side doublers in the position shown on the plan.
Check to determine how it fits. Note that the switch
slot should be in the front. Sand the sides of the servo
tray if necessary for a good fit between the balsa fuse
sides.
INSTALL THE SERVOS
Note: The following instructions and photos de- SPECIAL NOTE : If your battery pack is the flat
scribe how to install Futaba S-28 servos in your PT40. type (as shown on the fuse plan side view), it will fit
If your radio equipment is different from that shown nicely under an 8 oz. fuel tank in the front compart-
in the photos, you may have to use a slightly different ment. If your battery pack is the square type you
method to mount your servos properly. Be sure to will either have to use a 6 oz. fuel tank or place the
read the instruction manual for your radio before battery behind F-2. If this is the case, allow room
beginning this section. If you have difficulty with the for the battery behind F-2 by mounting the servo
radio installation, ask an experienced model builder tray 1-3/4" behind F-2.
for assistance.
D 6. Remove the tray. Apply 5- minute epoxy to
SPECIAL NOTE: Most radio systems sold the top of the lower portion of the plywood fuse side
today have "servo reversing switches" on the trans- doublers where the tray will rest, then lay the servo
mitter, which enable the modeler to install the ser- tray in place and allow the epoxy to harden.
24
D 7. "Lock" the servo tray in place by gluing a few
scraps of 1/8" ply (from the die- cutting scrap) to the
fuse side and the top of the servo tray using thick
CA as shown here.

D 13. Screw the aileron servo to the mount using

the screws provided with your radio.

D 8. Put the servos into the tray and screw them

down with the screws provided with your radio.
Tighten the screws "finger tight , not wrench tight".
D 9. Make a single servo mount as described below,
for the aileron servo. This is only required for Wing
B. If you built Wing A, skip to the next section.
From 1/8" plywood die-cutting scraps, cut one
piece 1-1/8" wide x 2-7/16" long. Also cut two pieces
3/8" wide x 1-3/16" long, with the wood grain running INSTALL NYLON CONTROL HORNS
the long way. From the 3/8" x 5/8" x 2-1/2" balsa pro-
vided, cut two triangular servo rail braces. Use the D 1. Find the set of two nylon control horns and
pattern shown here: cut them apart with an X-acto knife. Also find the
four 2-56 screws that are 5/8" long.

2-56 x 5/8" SCREW

Glue the above five parts together to make the

single servo mount. Study the plan to see how they
go together.

D 2. Remove the rudder and elevator from the fin

and stab. Remove the hinges.
D 10. While holding the servo in place on the rails,
D 3. Lay the rudder on the fuselage plan side view
mark the location of the four mounting holes through
and determine where the nylon control horn should
the brass eyelets onto the plywood. Drill 1/16" holes
be located. Holding one of the nylon horns in place
at these marks.
on the left side of the rudder, use a pencil to mark
D 11. Attach a large servo wheel to your 4th servo. through the holes in the horn.
D 12. Determine from the plan (See the "Bottom of D 4. Drill 3/32" holes through the rudder at the
Wing" detail) exactly where this aileron servo mount marks you just drew.
should be located. Lay the mount in place on the
D 5. Repeat steps 3 and 4, locating and drilling
bottom of the wing and using a felt-tip marker, draw
holes in the elevator. Note: When marking the lo-
a dark line around the base of the servo mount. DO
cations for drilling, you must hold the nylon horn
NOT GLUE THE SERVO MOUNT TO THE WING
on the BOTTOM of the elevator!
UNTIL AFTER COVERING.

25
D 6. Temporarily mount the control horns on the D 6. Take one of the 12" threaded wires, attach a
rudder and elevator. (Note that the elevator horn is clevis and bend the wire to match the drawing of the
mounted on the bottom, and the rudder horn is elevator rear pushrod wire (top view). At the front
mounted on the left side.) To do this, insert two 2-56 end of this wire drawing, note that the wire makes
screws through the holes in the horn and through a 90 degree bend and goes into the dowel. Make this
the holes you drilled. Then screw them into the nylon bend now, and cut the wire off.
"nutplate" which originally came attached to the
horn.
D 7. Re-install the rudder and elevator onto the fin
and stab, but do not glue in the hinges.

PUSHRODS
D 1. Get the following parts together before start- D 7. Round both ends of the dowel slightly to help
ing: prevent the possibility of it "hanging up" on some-
thing.
2- 1/4" diameter hardwood dowels, 25" long
D 8. With 100 grit sandpaper, roughen the end of
6- 12" long wire, threaded one end the wire that will be glued to the dowel.
2- small nylon aileron clevis connector D 9. Insert the wire into the hole and the groove
2- n y l o n a i l e r o n c l e v i s in the dowel. Apply a couple drops of thin CA to hold
in place.
4- standard nylon clevis
D 10. Wrap kite string or strong thread around the
10 feet of kite string or strong thread (not wire and dowel as shown on the plan, then apply
supplied) thick CA onto the string.

D 2. Write "elevator pushrod" on one of the 1/4" x

25" dowels, and "rudder pushrod" on the other.
D 3. Lay the elevator pushrod dowel on the fuselage
top view. Note that the front pushrod wire attaches
to the top of this dowel, and the rear wire attaches
to the right side. To avoid confusion later, draw lines
l-3/8"long on the dowel where the wires will be at- D 11. After cutting the pushrod wire to length in
tached. step 6, you should have a straight piece of wire re-
maining that has a length of about 6-1/2 inches. Make
D 4. Use the threaded end of one of the wire push- a short 90 degree bend in one end of this rod.
rods to "file" grooves in the dowel where you drew
the lines. The grooves need not be deeper than 1/2 D 12. Roughen the end of the rod near the bent end
the thickness of the wire. using sandpaper.
D 13. Insert this rod into the hole and groove in the
front end of the elevator pushrod dowel, wrap with
thread and apply thick CA.
D 14. Following a similar method as given in steps
3-13, make the "Rudder Pushrod". Note that the
groove in the front of the rudder pushrod is on the
top of the dowel while the groove in the rear is on
D 5. Drill 5/64" holes through the dowel, 1-3/8" in the left.
from each end, at the end of the grooves you made
in step 4.

D 15. Remove the nylon clevises from the rear ends

of the elevator and rudder pushrods.
D 16. Insert the pushrods into the fuselage through
the openings in Formers 3-6 and out through the
slots in the fuse sides that you previously cut.
26
 D 17. Screw the nylon clevises back on the rear ends B-Bend up with pliers.
of the pushrods. Pry the clevises open with a screw-
driver and hook them up to the outer holes in the
nylon elevator and rudder horns. Twist the pushrods
slightly, so the rods come out of the fuse side slots
without binding.

C-Finish Z-bend.
D 18. Temporarily hook up the receiver, battery
pack, switch and servos. Read the instruction man-
ual for your radio to learn how to do this.
D 19. Center the "trim tabs" on your radio transmit-
ter for the elevator, aileron and rudder controls. The
trim tab for the throttle should be pushed all the
way forward.
D 20. Turn on the transmitter and receiver so the
servos rotate to their normal "centered" positions.
Now turn off the receiver and transmitter (in that
D 24. Now you may re-install the pushrods and in-
order).
sert the Z-bends into the servo wheels. Note: To do
D 21. With the rudder centered (straight with the this you must remove the servo wheel from the servo,
fin) lay the front part of the rudder pushrod across drill out the hole in the servo wheel to 5/64" diameter,
the hole in the servo wheel where it will attach. Using work the Z- bend into the hole, and replace the servo
an indelible marker, make a small mark on the push- wheel on the servo.
rod at the hole location.
D 25. Turn the radio on, and check the movement
of the elevator and rudder. To re-center the elevator
and rudder, turn the clevis on the rear end of the
pushrod.
D 26. From die-cutting scrap, cut two pieces of 1/8"
plywood 1/4" wide and 2-3/4" long. Glue these "push-
rod braces" to the front of F-4, above and below the
pushrod dowels, as shown in the drawing of F-4 on
the bottom of the fuse plan.
D 27. To provide adequate movement to move the
D 22. Center the elevator and mark the pushrod throttle from full power to idle, you will probably
where it goes across the hole in the elevator servo have to use a longer servo arm than the small wheel
wheel. which is standard on the servo. Take one of the 4-arm
servo arms and cut off three of the arms.
L_] 23. Remove the elevator and rudder pushrods from
the fuselage and make "Z"-bends in the pushrods at D 28. With the long arm attached to the throttle
the marks you just made. Here's how... servo, as shown on the fuse plan top view, lay a pencil
across the top of the arm and make a mark on the
A-Bend down with pliers. back of F-2. Also make a mark for the nose gear
pushrod hole. Note: Also see the drawing of F-2 near
the bottom of the plan.

27
D 29. Use a drill with a 1/8" bit to drill holes through B-Moving the Z-bend to a different hole in the
F-2 for the throttle and nose gear pushrods. servo arm (outer hole gives more movement than
the inner hole).
C- Turning the nylon clevis on the pushrod.
D 36. Re-mount the nose gear bearing, steering arm
and the nose gear.
D 37. Take the final pushrod wire, attach a clevis
and bend the wire to match the nose gear pushrod
drawing on the fuse plan side view, but do not make
the Z-bend yet and do not cut off the excess wire.
D 38. Insert the pushrod through the holes in F-2
D 30. Bend one of the pushrod wires that has a clevis and F-l with the clevis at the servo end. Attach the
attached so it runs freely from the throttle arm on clevis to the servo wheel.
your engine to the throttle servo.
D 31. Turn on your transmitter and receiver, and
push the throttle stick and the throttle trim tab (left
side of the transmitter) fully forward. Now turn off
the receiver and transmitter (in that order). The servo
arm should now be angled forward about halfway.
D 32. Insert the throttle pushrod through the holes
in F-l and F-2 and attach the nylon clevis to the
throttle arm on your engine.
D 39. With the nose gear centered (not turning right
or left), mark the location of the hole in the steering
arm on the pushrod using an indelible marker.
Note: The nose gear pushrod attaches to the
servo wheel on the opposite side of the rudder push
rod attachment.
D 40. Remove the nosegear pushrod and make a
Z-bend at the mark you just made. Cut off the excess
wire.
D 33. With the pushrod in place and the carburetor D 41. Remove the clevis and re-insert the nose gear
wide open, mark the location of the servo arm hole pushrod through F-l and F-2. Re-install the clevis,
on the pushrod using an indelible marker. hook it up and check for proper operation.
D 34. Remove the throttle pushrod and make a Z- Note:To attach the Z-Bend to the steering arm,
bend at the mark you just drew and cut off the excess you must remove the arm from the nose gear first.
wire. Note: To re-insert the throttle pushrod, you will Attach the Z-Bend and then put the steering arm
have to remove the clevis and slide the pushrod in back in place. Adjustments to re-center the nose
from the rear. Do so now. wheel are made by turning the clevis at the servo
D 35. Turn on the radio and check the operation of end of the pushrod.
the throttle. With the throttle stick and trim fully
forward the carburetor should be fully open. With
the throttle stick fully back and the trim fully forward
the carburetor should be open just a very small
amount. With the throttle stick and the trim fully
back the carburetor should be fully closed. The servo
must not bind or "buzz" at the full- forward or full-
back positions.
Note: Adjustments made in this set-up are
made by:
If you built Wing A, skip to the next section.
A-Moving the clevis to a different hole in the
throttle arm (outer hole gives less movement than
inner hole) D 42. Temporarily tape the aileron servo mount in
place on the bottom of the wing.

28
 BALANCE THE AIRPLANE LATERALLY

SPECIAL NOTE: Do not confuse this pro-

cedure with "checking the C.G." or "balancing
the airplane fore and aft". That very important
step will be covered later in the manual.

Now that you have the basic airframe nearly

completed, this is a good time to balance the airplane
laterally (side-to-side). Here is how to do it:
D 43. Find the two small white nylon aileron clevis
connectors and screw them about halfway onto the D 1. Temporarily insert the wing hold down dowels
threaded aileron torque rods. into the fuselage, and attach the wing with about
four #64 rubber bands.
D 44. Screw the two white nylon clevises onto the
threaded pushrod wires that do not have clevises D 2. Start with the fuselage resting on a level table
attached. Screw them on 12 turns, which is halfway. with the nose gear off one edge of the table.

D 45. Bend the aileron pushrods to match the pat- D 3. Grasp the propeller shaft of the engine and
terns shown in the "BOTTOM OF WING" detail on lift, so the airplane is being supported only by the
the wing plan. propeller shaft and the bottom of the rudder. Do this
several times.
D 46. Attach the nylon clevises to the clevis connec-
tors. D 4. If one wing tip always drops when you lift, it
means that side is heavy. Balance the airplane by
SPECIAL NOTE: To insure adequate roll adding weight to the inside edge of the other wing
(aileron) control at low speeds, it is necessary to set tip rib. A good way to add weight to the tip is by
up the aileron pushrod linkage so the ailerons move sticking several small nails (brads) or tacks into the
upward a lot more than downward. This is called tip rib, from the inside. Add only a few nails or tacks
"differential throw". If you study the "BOTTOM at a time, securing each one with a drop of thin CA
OF WING" details you will see how this is ac- then re-checking the balance.
complished. You must use a large servo wheel, and
attach the pushrods off-center, as shown in the draw- Note: In preparation for the next part, remove
ing. all pushrods, all radio equipment (excepting the
switch), nose gear bearing, nylon aileron clevis con-
D 47. Drill two 5/64" holes in your large servo wheel, nectors, nylon rudder and elevator horns, engine, rud-
about 45 degrees off- center. The Futaba large servo der, elevator, ailerons and all hinges. Before remov-
wheel has lines that radiate out from the center every ing, you may wish to pre-mark any parts that may
45 degrees. cause confusion when re-assembling them later.
D 48. With the servo wheel and the ailerons cen- ADD THE FUSELAGE TOP
tered, hold the aileron pushrods in place over the
holes in the servo wheel, and mark the hole locations D 1. With your T-bar and 100 grit sandpaper, sand
on the pushrods using an indelible marker. the top of the fuse sides, upper lockplates and the
formers smooth and flat.
D 49. Remove the pushrods and make Z-bends at
the marks you just made.

D 2. Lay the pre- shaped 1/8" balsa fuse top in

place against the front of the stab. The front edge of
the fuse top must be even with the front edge of F-3.
D 50. Re-install the aileron pushrods, work the Z-
If not, cut or sand a small amount off the rear edge
bends into the servo wheel, hook up the aileron servo
of the fuse top. Continue cutting and checking until
to the receiver using the aileron extension cord
the fuse top is the correct length.
provided with your radio system, and check the oper-
ation of the ailerons. D 3. Mix up some 5 minute epoxy and apply it to
the tops of F-4 and F-5 only. Immediately lay the
fuse top in place and apply thin CA glue all around
29 the edges.
 SAND THE FUSELAGE NOTE ON COVERING TOOLS:
D 1. Use your T-bar with 100 grit sandpaper to Since we recommend that you use a plastic cov-
sand the entire fuselage smooth. Pay special atten- ering such as Super Monokote to finish your PT40,
tion to the glue joints, as they will show right through you'll need to be aware of the tools you'll need to
the covering if left bumpy or uneven. Round all edges borrow or buy to apply the covering to the model.
slightly, excepting the wing saddle area and the The covering itself has an adhesive on the side that
hatch saddle area, to make it pleasing to the eye. goes toward the wood. The covering is heated so it
will stick to the wood. A sealing iron and a heat gun
were made expressly for applying this type of cover-
ing. You'll also need an X-Acto knife with a new blade
or scissors to cut the covering.

NOTE ON COVERING SEQUENCE:

We recommend that you start with the stab
bottom and then do the stab top, fin, elevator, rudder,
ailerons (if you built Wing B), the fuselage and then
the wing.

D 2. Now change to a T-bar with 220 grit sandpaper GENERAL COMMENTS

and go over the entire fuselage again, final sanding Pieces of covering are cut about an inch over-
it very smooth. size. The covering is laid into position on the bottom
FUELPROOF THE ENGINE AND FUEL of the part, such as the stab, after the backing is
TANK COMPARTMENTS removed. The covering is tacked (touched with the
sealing iron) in a few places along the edges, then is
Note: Most of the model's surfaces will be sea- sealed along the edges with the sealing iron, leaving
led and protected by the covering material you use; a small opening at one edge for a vent. Then the
however, the engine and tank compartments would sealing iron is placed over the rest of the covering in
be difficult and impractical to cover, so you must pro- from the edges, heating it. Quickly seal the area with
tect these areas by brushing on one or more coats of a small rag by lightly rubbing the area. Then seal
"fuel proof paint which is available from your local the vent you left open. If you get any bubbles, pick
hobby dealer. Or, instead of paint, you may mix up them with a pin and reseal. Now seal the covering
some 30 minute epoxy, thin it to a brushing consis- around any edges and trim with your knife without
tency by adding a little rubbing alcohol and brush cutting into the wood. The top of the part is then
it on. covered, overlapping the edges and trimmed under-
neath so you won't see the seam when the plane is
D 1. Fuelproof the inside surfaces of the engine
on the ground. Using this covering and these tools
compartment, including the engine beams, balsa
is not really difficult but takes some practice to get
triplers, and the front of F-l.
really nice results. So practice and you'll be pleased
D 2. Fuelproof the breakaway plates. how nice your models will look.

D 3. Fuelproof the inside of the fuel tank compart- COVER THE STABILIZER
ment, including the bottom of the hatch. D 4. Start at the corner of the fuselage. Fold 1/4
PREPARE THE MODEL FOR COVERING inch of the covering up against the fuse side and
anchor it in place with your sealing iron. Then tack
D 1. Check the fuselage and the wing for any dents and fasten the rest of the covering. You want to have
you might have put in the wood. A small amount of a good seal at the stab/fuselage joint so oil from the
water placed on the dings will repair them. The water engine exhaust won't soak into the wood.
causes the balsa to swell, removing the dings au-
tomatically. Use balsa filler on larger dings. Sand COVER THE FIN, RUDDER AND
the balsa filler to a smooth finish using fine grade ELEVATOR
sandpaper. You should have already final sanded your D 5. Use the techniques mentioned above and cover
PT40 but give it another sanding with fine paper. these parts. The seal at the fin/fuselage joint is impor-
The better the finish at this stage the better the tant, so seal it well.
covering will look.
COVER THE FUSELAGE
D 2. Wipe all the dust from the model with a tack
rag or vacuum with a hand held attachment. Tack D 6. Start at the bottom. The bottom covering
rags are sold at hardware stores and are chemically should overlap the sides by 1/4 inch. Lay the covering
treated so they will clean surfaces prior to painting. in position, tack and seal the edges. Leave the tail
and nose open slightly for trapped air to escape. Now
D 3. Make sure all hardware, engine etc. is out of use the heat gun and rag and fasten the rest of the
the model so you can do a good job of covering. covering.
30
D 7. Do the sides next. Tack and seal the edges, D 14. Cover the top of the other wing panel making
vent at the nose and tail and finish the job. Trim the sure you overlap the covering at least 1/2" at the
covering flush with the bottom and flush at the top center.
also.
D 8. Cover the top of the fuselage. Do this in two
parts, the rear and the front of the fuselage on either
side of the wing saddle area. Tack and seal the edges.
Finish the top area with the heat gun and rag. Bring
the top covering down 1/4 inch over the sides. Trim
and seal it.
D 9. Carefully cut away the covering from the fuse
sides where the wing hold down dowels will be in-
serted. Smear 5-minute epoxy on the dowels and in-
sert them so they stick out the same on both sides.
Wipe off the excess epoxy with a tissue. After the
epoxy sets you may either cover or paint the exposed SPECIAL NOTE: The above instructions for
ends of the dowels. covering told you how to cover with one color. You
can get a little fancier and use a second color for trim
COVER THE WING like we did on ours on the box lid. If you use two
colors, cover with the lightest color first, like the
D 10. Cover the tips first with 3" x 12" pieces of white on ours. The white was put on the fuselage
covering material. Iron the covering down to the flat side about halfway down. Then the red was cut with
ends of the tips, then pull and stretch the covering a straight edge, tacked and sealed at the red/white
around the comers while heating with the iron. Trim seam and then tacked and sealed at the bottom. A
off the excess. heat gun was then used to finish. The rest of the
D 11. Now cover the bottom of one wing panel, over- plane was covered totally in white and then pieces
lapping the center of the wing by at least 1/4". First of Super MonoKote red were cut to shape and adhered
iron the covering down to the center of the wing and with a heat gun and rag to the white. Just the top
at the tip. Next, seal the covering to the trailing edge of the wings have the red trim. You usually want the
and the leading edge (the covering should wrap at top of the wings to look different than the bottom so
least halfway around the leading edge). Once sealed you can tell what the airplane is doing in the air.
all the way around, you may shrink the covering tight
with a heat gun. Hold the heat gun a few inches away After the red trim was added, we put
from the covering, and keeping it moving, so you some of our 1/16" black striping tape along the red
don't melt through. Finally, use the iron to seal the for more trim. We used gray Super MonoKote for the
covering to the spars. windows, masked them off and spray painted black
around the edges to give the windows some depth.
D 12. Cover the bottom of the other wing panel in You can follow our trim scheme or create your own!
the same manner as above. Use your imagination and have fun creating your
very own PT40.
ADD "WASHOUT" AT THE WING TIPS
SPECIAL NOTE: When covering the top of
the wing, make sure the top covering overlaps the SPECIAL NOTE: One important flying
bottom covering by at least 1/4" at the leading edge. characteristic of the PT40 is its ability to recover
"hands-off" from a steeply banked turn. This is made
D 13. Next, cover the top of one of the wing panels. possible by building the wing with DIHEDRAL and
At the center of the wing, allow the covering to over- WASHOUT. You will add washout to each wingtip
lap the center ribs by about 1/2" . Slit the covering by intentionally warping the wing panels, so that
at the spars, then iron it down to the side of the the trailing edge will be higher than the leading
center rib, as shown in the following photograph. edge at each wingtip. Here's how to do it...

31
D 1 Have someone hold the center of the wing A Place the fuselage on the work surface right
firmly down to the flat building surface Now grasp side up Place the wing into the wing saddle Make
the tip of the wing and twist it so that the trailing the following measurements If the distances you
edge raises off the surface While holding in this measure are not the same, move the wing in the wing
twist, use a heat gun to "re-shrink" the covering. saddle until the measurements are the same.
Heat both the top and the bottom When you let go
of the tip, you will see that the wing will retain some
of the twist.
D 2. You must continue twisting and re-shrinking
until the trailing edge is 7/8" off the surface AT
BOTH TIPS As an aid in getting this height correct,
you may make a small wood block 7/8" high by gluing
together pieces of scrap wood Keep this block handy
while twisting and heating, to check your progress.
D 3. Depending on what type of covering you have
used, you may find that, in time, some of the washout
may disappear Check it after an hour and repeat the
above process if necessary Also, re- check it periodi-
cally before you go flying, because THIS IS A VERY
IMPORTANT REASON FOR THE STABILITY OF
YOUR PT40
D FINAL ASSEMBLY
D 1 Lay the rudder and elevator (and ailerons if
you built Wing B) on the plans and mark the hinge
locations on the leading edge of each part Now use
your X-Acto knife (blade must be sharp) to cut slits
in the covering at the hinge locations Trial fit the B Measure the wing from side to side in the
hinges to make sure you have "found" the slots which saddle The distance from the fuselage side to the
you previously cut wing tip on each side should be the same. A = A
L] 2. Glue the hinges into the rudder and elevator C Measure from each wing tip to each stab tip.
(and ailerons) NOTE Do not just smear glue on the These distances should be the same. B = B
hinge and push it into the slot, as most of the glue
will be wiped off as it is being pushed in You must D Wing tip to work surface distance is the same
also work some glue into the slot A good way of doing on both sides C = C
this is to scoop up some epoxy with a plastic soda E When the wing is all lined up to the fuselage
straw, then pinch the end of the straw, insert it into after the above measurements are made, mark a
the hinge slot, and squeeze the straw to force glue small line on the wing and a small line on the fusel-
into the slot Then insert the hinge hallway into the age drawn with a pen on the covering, so you can
slot After pushing in the hinge, wipe away all excess put the wing in the same position each time before
glue with a tissue. you rubber band it.
D 3. After the epoxy has hardened, put glue (15 or D 7. Re-install the nose gear assembly, main land-
30 minute epoxy is recommended) into the hinge slots ing gear, engine and muffler.
in the stab, and push the elevator hinges into the
slots Wipe away all excess epoxy with a tissue. Re- D 8 Re- install the nylon horns on the elevator
peat this process for the rudder and rudder For the rudder, you will have to re-drill
D 4 Wing B only Glue the aileron hinges in place the two holes for the 2-56 screws because the lower
in the same manner, but also apply epoxy into the hinge now blocks the holes.
torque rod holes before pushing the ailerons into D 9 WING B ONLY- Using a sharp X-Acto knife
place. or single edge razor blade, carefully cut away the
covering from the bottom of the wing where the aile-
D 5. Install 1/4" wide wing seating tape (sticky
ron servo mount will be attached You should be able
side down) onto the wing saddle and the top of the
to faintly see the dark outline that you previously
F-2A (or F-2B) saddles
drew under the covering Now glue the aileron servo
D 6 Note- Each time you put the wing into the mount to the bottom of the wing.
wing saddle to fly the model, it needs to be in the
D 10. Using an X-Acto knife, cut away the covering
same position Follow the steps below so the wing
from the rudder, elevator and nose gear pushrod slots;
will be in the correct relationship to the fuselage.
then re-install the pushrods for the rudder, elevator,
throttle, nose gear and (ailerons).
32
D 11. Cut a hole in the center of the fuse top, about ting on the carburetor. Run a second piece of tubing
2" behind the wing saddle, and glue in a 2-1/2" length from the tank "vent" through the hole in F-l to the
of fuel tubing to serve as an antenna exit (see the pressure tap fitting on the muffler. To prevent fuel
fuse plan). foaming the tank must be isolated from direct con-
tact with the fuselage, so add foam rubber in front
D 12. Wrap foam rubber around the receiver and and on top of the tank before replacing the hatch.
hold the foam in place with a couple of rubber bands.
Now you must attach the receiver to the fuselage in D 18. Install the wheels on the main landing gear
such a way that it does not move around, but at the and nose gear using 5/32" wheel collars on both sides
same time it must be cushioned from vibration. A of each wheel
good method for accomplishing this is to secure two
hooks down in the bottom corners of the fuselage,
and rubber band the receiver down.
RECEIVER (AND
BATTERY) MOUNTING

SPECIAL NOTE: If you plan to f l y from a

concrete, blacktop or smooth grass field, use 2-1/2"
diameter main wheels and a 2-1/4" diameter nose
wheel. However, if the field you will be flying from
is rough or has fairly long grass, we recommend using
2-3/4" main wheels and a 2-1/2" nose wheel. In either
case, you should bend the main landing gear if neces-
sary so the model sits level or slightly nose down
when at rest.
-BASSWOOD BLOCK BOTTOM
(SCRAP FROM WING SPAR) D 19. Install the proper size propeller for your engine
D 13. Wrap the battery pack in foam rubber, place (see your engine instruction manual), and a 2-1/4"
it in a plastic bag, and close it with a couple of small diameter spinner. Note: If you choose not to use a
rubber bands. Now secure the battery pack in the spinner, you should ( for safety reasons) use a rounded
bottom of the fuel tank compartment in the same "acorn"-type prop nut to hold the propeller on.
manner as you did the receiver. Also place a piece of
foam rubber between F-l and the battery pack. SPECIAL NOTES ON PROPELLERS: Vib-
D 14. From scraps of plastic, make the "antenna st- ration is the main enemy of the electronic and
rain relief and the "antenna clip" (unless your radio mechanical parts in an R/C airplane, and an out-of-
system includes these). Pass the receiver antenna balance propeller is the primary source of the hard
wire through the holes in the plastic strain relief vibrations that cause problems. For only a few dollars
piece, then through the antenna exit tube. Adjust you may purchase a prop balancer. We highly recom-
the position of the strain relief such that the portion mend that you do so, and carefully balance each prop-
of the antenna inside the fuselage remains loose, eller before bolting it on your airplane.
even when you pull on the end of the antenna. Now Always use propellers that are in perfect shape.
attach the end of the antenna to the top of the fin Discard any prop with nicks, scratches, splits or
using your antenna clip, a small rubber band and a cracks or any sign of wear and damage. Never repair
pin. Note: The receiver antenna is "tuned" for the or alter a prop (propeller).
frequency on which the radio will operate, so do not
cut off any of its length. Just allow the excess to trail Paint the prop tips white so you can see the
behind. ends when the prop is spinning (this is especially
important if you are using one of the black fiberglass-
D 15. Plug the servo wires into the receiver and hook
filled nylon props).
up the battery and switch (refer to your radio instruc-
tion manual for guidance). Install the prop with the curved side facing
forward. Securely tighten the prop nut. Inspect the
D 16. The fuse top view shows a piece of 1/16" wire prop and re-tighten the nut after every few flights.
passing through the switch and out the side of the If you install a spinner, make sure the edges of the
fuse. This enables you to switch the receiver on and spinner do not touch the prop blades.
off without removing the wing. Install a remote on/off
switch pushrod similar to the one shown. D 20. While standing behind the model, adjust
the servo reversing switches on your transmitter so
D 17. Lay the fuel tank in place on top of the battery the elevator, rudder, throttle (and ailerons) move in
pack. Run a piece of fuel line tubing from the fuel the correct directions as follows:
pick-up ("klunk") through the hole in F-l to the fit-
33
 given below, with full movement of the transmitter
sticks.

ELEVATOR = 3/16" up and 3/16" down

RUDDER = 3/16" right and 3/16" left
AILERONS = 7/16" up and 1/8" to 1/4" down

D 23 Write your name and address plainly on a

piece of paper and glue the paper inside the fuselage
onto one of the fuse sides If you lose your model the
finder will know who to contact
D 24. Temporarily attach the wing with 10 or 12
good #64 rubber bands
REMEMBER Proper installation of all R/C
components and accessories is crucial to the safe and
proper operation of your model, and that improper
or faulty installation of even one component or acces-
sory may result in damage or destruction of the entire
model, as well as cause serious personal injury or
property damage Therefore, if you are confused or
uncertain about any of the above final assembly
steps, please ask an experienced model builder for
assistance
BALANCE YOUR MODEL
NOTE: THIS STEP IS VERY IMPORTANT,
AND MUST NOT BE OMITTED!
D 1 With the wing rubber banded to the fuselage,
all parts of the model installed, and an empty fuel
tank, gently turn the model upside down.
D 2 By feel, determine the location of the center
of the main wing spar in the vicinity of the 2nd wing
rib (where the bottom center section balsa sheeting
ends).
D 3 From the center of the main wing spar, measure
exactly 5/8" back (toward the tail) and make a mark
Do this on both sides of the wing bottom Note For
ease of checking the balance, you may stick a
thumbtack into the bottom wing sheeting at these
balance point marks.
D 4 Turn the fuselage right side up, place your
index fingers under the wing and lift the airplane
at the balance point If the tail drops when you lift,
the model is "tail heavy ' and you must glue weights
into the nose of the model, either in the engine area
or fuel tank compartment until it balances right on
the balance point On the other hand, if the nose of
D 21 By turning the clevises on the threaded ends the model drops when lifting, the model is "nose
of the pushrods, adjust the elevator and rudder to heavy" and you must glue a small amount of weight
the neutral (not up or down) positions Also (for Wing to the tail (under the stab, near the fuse) until it
B) adjust the aileron pushrod clevises so the bottom balances right on the balance point
of the ailerons are even with the flat bottom of the
wing FLYING
Note The throttle pushrod should already be IMPORTANT: Regardless who you are or
properly adjusted according to "PUSHRODS", Step where you live, we strongly urge you to seek the
35 assistance of a competent, experienced R/C pilot to
check your model for airworthiness AND to teach you
D 22 Adjust the pushrod hookups so the elevator, how to fly No matter how stable or "forgiving" your
rudder (and ailerons) move the correct amounts, as 34
model is, attempting to learn to fly on your own is Keep all engine fuel in a safe place, away from
dangerous and may result in serious or even fatal high heat, sparks or flames as fuel is very flammable.
injury to yourself and others, and total destruction Do not smoke near the engine or fuel, remember that
of your model Therefore, find an instructor (even if the engine exhaust gives off a great deal of deadly
it means driving a long distance) and fly only under carbon monoxide Therefore do not run the engine in
his or her guidance and supervision until you have a closed room or garage.
acquired the skill necessary for safe and fully control-
led operation of your model Get help from an experienced pilot when learn-
ing to operate engines
CHARGE THE BATTERIES
Use safety glasses when starting or running
Follow the battery charging procedures in your engines.
radio instruction manual You should always charge
your transmitter and receiver batteries the night be- Do not run the engine in an area of loose gravel
fore you go flying, and at other times as recommended or sand, the propeller may throw such material in
by the radio manufacturer your face or eyes.
1. FLY IN A SAFE PLACE Keep your face and body as well as all spectators
away from the path of the propeller as you start and
1. The best place to fly your R/C model is an AMA run the engine
chartered club field Ask your hobby shop dealer if
there is such a club and join Club fields are set up Keep away from the prop loose clothing, shirt
for R/C flying which usually makes your outing more sleeves, ties, scarfs, or loose objects (pencils, screw
enjoyable The AMA can also tell you the name of a drivers) that may fall out of shirt or jacket pockets
club in your area We recommend that you join AMA into prop.
and a local club so you can have a safe place to fly
Use a "chicken stick" device or electric starter,
and also have insurance to cover you in case of a
follow instructions supplied with the starter or stick
flying accident
Make certain glow plug clip or connector is secure
If a club and its flying site are not available, so that it will not pop off or otherwise get into running
you need to find a large, grassy area at least 6 miles propeller
away from any other forms of radio operation like
Make all engine adjustments from behind rotat-
boats and cars and also is away from houses, build-
ing propeller.
ings and streets A school yard may look inviting but
it is too close to people, power lines and possible radio The engine gets hot! Do not touch it during or
interference after operation Make sure fuel lines are in good con-
dition so fuel is not leaked onto a hot engine causing
2. RANGE CHECK YOUR RADIO
a fire
Wherever you do fly, you need to check the op-
To stop engine, cut off the fuel supply by closing
eration of the radio every time you fly This means
off the fuel line or follow the engine manufacturer's
with the antenna down, and the receiver and trans-
recommendations Do not use hands, fingers or any
mitter on, you should be able to walk 100 feet away
body part to try to stop the engine Do not throw
from the model and still have control Have someone
anything into the prop of a running engine
help you Have them stand by your model and while
you work the controls, tell you what the various con- The instructor will usually tell you about flying
trol surfaces are doing If the control surfaces are not rules at the field The number one rule you should
acting correctly, do not fly Correct the problem first. always adhere to is -Do not turn on your radio system
before you first check out what frequencies people
3. GROUND CHECK THE MODEL
are using at the time If you turn on your radio system
The instructor will check to see that you have while someone is flying on your frequency, you could
the radio installed correctly and that all the control crash their airplane This is called "shooting someone
surfaces do what they are supposed to He/she will down" No one wants all their hard work ruined be-
check the engine operation and help you "break in" cause someone wasn't thinking and turned on their
the engine on the ground This means that you will transmitter at the wrong time. Always try to re-
run the engine and use up at least two tanks of fuel member this rule
to let the engine get broken in Adjustments are made
The instructor will check the model over to
to the carburetor so the engine runs at its best The
make sure all the screws are tight and that the prop
instructions that come with the engine will tell you
is tight He/she will check hinges to see if they are
how to break in the engine
securely glued The instructor therefore checks all
ENGINE SAFETY PRECAUTIONS parts of the model to see if it is airworthy The instruc-
tor will recommend changes to be made before the
Note Failure to follow these safety precautions model is ready for flight.
may result in severe injury to yourself and others.

35
4. TRIM OUT THE MODEL box system The instructor has his or her transmitter
attached to yours by a cord There is a switch on the
Trimming the model means that you have an instructor's transmitter so he/she can control who is
experienced flier fly the model and make final adjust- flying the model If you get into trouble, the instruc-
ments to the amount of throw in the control surfaces tor can switch the control back to him/her and get
The distances for the control surface throws we gave the model flying safely again The instructor will
you previously are close to where they should be take the plane up to a safe altitude and then let you
But you won't really know until the plane is in the take over to practice for 2 or 3 minutes Then the
air Slight changes need to be made The experienced instructor can land the model for you As you prog-
flier, usually an instructor from a local club, will ress, you then learn to land the plane and take it off
know what to change as he or she flies the model by yourself and then to do a complete solo'
The instructor will adjust the trim levers on the radio
transmitter to make the model fly straight and level If it is absolutely necessary for you to learn
with the control sticks in neutral Then when the by yourself, go to your hobby shop and buy some
plane is on the ground he or she will adjust the books on flying models Learn all you can before you
clevises at the rudder, elevator and ailerons so the actually take the plane up Take your time and don't
trim levers can be moved back to neutral (As you try to do everything at once You'll have to take the
become more experienced, you can trim out your new plane off, do some turns and then land it again with-
models yourself The first flight for any new plane out crashing it Have a flight plan in mind before
should be used to trim out the model) Trim changes you take off Following is a sample flight plan you
may be needed anytime so keep checking to see how might want to follow for those first critical flights
the control surfaces react to the stick movements. Study this flight plan and run through it on the
ground Practice moving the controls on your trans-
5 LEARNING TO HANDLE THE MODEL ON THE mitter and imagine what the plane is doing The
GROUND more you practice on the ground, the easier it will
be in the air
After your instructor makes sure the model is
airworthy, it's your turn' The first thing you do is to Read and abide by the following Academy of
practice taxiing the model on the runway Choose a Model Aeronautics Official Safety Code:
time when there is very little wind to blow the model GENERAL
over on the ground Work the controls with a gentle
hand Don't push the sticks way over as far as they 1 I will not fly my model aircraft in competition or
go Give small amounts of right or left rudder to keep in the presence of spectators until it has been proven
the model heading straight down the runway As the to be airworthy by having been previously success-
model heads away from you, pushing the rudder stick fully flight tested.
to the right makes the model turn to the right and
2 I will not fly my model aircraft higher than approx-
pushing the stick to the left makes the model turn
imately 400 feet within 3 miles of an airport without
to the left Now turn the model around, slowly' Too
notifying the airport operator I will give right of way
fast and you could tip it over Now as the model comes
to, and avoid flying in the proximity of full scale
toward you, pushing the rudder stick to the right
aircraft Where necessary an observer shall be
makes the model turn left' The model is actually still
utilized to supervise flying to avoid having models
turning right but it looks backwards to you because
fly in the proximity of full scale aircraft
the model is coming at you now This is normal You
may want to turn your back on the model and look 3 Where established, I will abide by the safety rules
over your shoulder as you are learning to taxi. for the flying site I use, and I will not willfully and
deliberately fly my models in a careless, reckless and/
Keep practicing the taxi on the runway, keeping
or dangerous manner
the model in control at all times After awhile, look
straight at the model as it comes toward you without RADIO CONTROL
turning your back on it Push the stick in the direction
that the model is turning to make it turn the other 1. I will have completed a successful radio equipment
way Practice until you feel comfortable making the ground check before the first flight of a new or re-
model turn right and left and making it turn around paired model
and come back to you Set up some empty pop cans
2 I will not fly my model aircraft in the presence of
or something similar and practice going around the
spectators until I become a qualified flyer, unless
cans without knocking them over
assisted by an experienced helper
6. YOUR FIRST FLIGHT
3 I will perform my initial turn after takeoff away
The ideal way to leam to fly is to use the buddy from the pit, spectator and parking areas, and I will
not thereafter perform maneuvers, flights of any sort
or landing approaches over a pit, spectator or parking
area.

36
 LEFT
SAMPLE FLIGHT PLAN After the model is on the ground after that first
flight, you can stand back and say "I did it'" even
though the pattern you flew may not have been per-
'LEFT
fect and the plane didn't do what you wanted it to
/RIGHT do Hopefully, you got the model down in one piece
5 LEFT Turn off the transmitter and then the receiver Check
DOWNWIND
out the model Is the prop still ok All the screws
tight Any dings in the covering Always check the
TAKEOFF-GENTLE CLIMB
plane after each flight Fix any problems on the
LEFT
DOWNWARD ground They sure won't get fixed in the air
GLIDE RUNWAY
Make the model airworthy again, fuel it up and
1 Head the model into the wind Release the model take her up again Try flying the pattern again and
and slowly advance the engine to full throttle again until you feel comfortable Then try flying a
pattern you make up.
2 Make gentle right or left stick movements to correct
the take off run and make the model run straight Remember, practice and practice You will have
down the runway a few setbacks, we all do when learning Just don't
give up and have fun while you leam Radio Control
3 As the speed builds up, give a slight amount of model airplane flying is one of the most rewarding
"up elevator", pulling back on the elevator stick, and hobbies around It just takes a little work and practice
the plane will fly itself off the ground Don't give too to get there
much up elevator You don't want the nose to rise so
the model climbs too steeply CHANGING FROM 3 TO 4 CHANNEL
VERSION
4 Reduce the throttle slightly to give a nice gentle
rate of climb Keep the wings level with right and If you have constructed Wing A and set up your
left rudder with Wing A or right and left ailerons PT40 for 3-channel operation, it will serve you well
with Wing B Fly the plane to about 100 to 150 feet during the initial training phase of learning to fly
Don't fly it so far away that you can't see it R/C After you have become proficient at soloing your
3 channel PT40 (which may require 50 to several
5 Make a wide, gentle turn to the left by giving left hundred flights), you will then be ready to fly a more
rudder or left aileron stick Keep turning until the maneuverable airplane with 4 channels of control
model is heading downwind, which is back toward (including ailerons)
you Level the wings by centering the stick You may
have to give a little opposite stick to level it out Assuming your PT40 is still in good condition,
you may wish to convert it to a 4-channel version
6 After the model passes you, start a very gentle left The best way to do so is to purchase a new PT40
turn Level it out and now do 2 or 3 figure eights, wing kit and build it up following the wing B instruc-
which are a series of right and left turns tions
7 After the last figure eight left turn, keep the plane Or: You may carefully cut the tapered trailing
flying upwind for a ways and then prepare for your edge off your wing and use it along with the aileron
landing Make a gentle left turn and fly downwind torque rod hardware to make ailerons for your wing,
past where you are as far as you flew upwind following the wing B instructions Note that this will
8 Make a gentle left turn and fly upwind and start produce a wing that has ailerons and the full dihedral
to judge where you want to land of Wing A We think you will find the results to be
satisfactory
9 Line the plane up with the runway Don't worry
too much if you don't land on the runway the first Or: You may cut the wing in half down the
time Just getting the plane down in one piece is center joint, cut away the covering in the center rib
your primary goal bays, re- join the wing halves at the Wing B dihedral
angle, gluing in the plywood dihedral braces
10 When you are sure you can reach the runway, cut found in the die-cut "B" sheet, cut off the tapered
the throttle slowly to give the plane a gentle down- trailing edge and use it along with the aileron torque
ward glide, not too steep Keep the wings level Don't rod hardware to make ailerons for your wing follow-
bring the nose up too much as the plane may stall ing the Wing B instructions Then re-cover the center
(the wings will lose their lift and the plane will tend of the wing Although this method produces a true
to drop and go out of control) "Wing B", it is the most difficult, so we urge you to
seek the help of an experienced modeler.
11 If you are going to land short of the runway, give
a little power to bring it in If you are overshooting
the runway and the plane is low enough and you KEEP MODEL AVIATION A SAFE SPORT!
have room in the grass, land it If you are too high,
give it throttle, a little up elevator, get back into the GOOD LUCK AND GREAT FLYING!
pattern and come around again for another try
37
 FLIGHT PROBLEMS
TROUBLE SHOOTING GUIDE

FLIGHT PROBLEM PROBABLE CAUSE RECOMMENDED SOLUTIONS

Does not automatically pull out of a 1 If dive continues straight ahead, the 1 (a) Re-trim the elevator for level flight
dive after elevator stick is released cause may be incorrect elevator trim (a) at 1/2 throttle.
or improper balance (b).
1 (b).Carefully balance the airplane, front
to back at the balance point shown on the
plan, 5/8" behind the center of the main
spar.

2. If dive results in a right or left 2. Re-trim the rudder and elevator for
turning spiral, the cause may be straight and level flight at 1/2 throttle.
incorrect elevator and/or rudder If this does not correct the problem, see
trim. below.

Does not automatically return to 1. Incorrect rudder trim. 1. Re-trim the rudder for straight flight
straight flight after a right or a left at all speeds.
bank after rudder stick is released
2. If rudder trim varies as speed is 2. Check alignment of vertical fin. If
changed, the cause may be incorrectly warped, twist while heating. If not
aligned or warped vertical fin. aligned with fuselage centerline, cut off
and re-install.

3. The airplane may not be laterally 3. Check lateral balance by lifting the
(side-to-side)) balanced. airplane at the propeller shaft and at the
aft end of the fuselage If one side drops,
add weight to the opposite wing tip to
balance.

4. The wing may be crooked in the 4. Check wing alignment by

saddle. measuring from both wing tips to
the top of the rudder hinge line
These measurements must be the same,
within 1/16" If not, re-position the
wing in the saddle.

5. Unequal or insufficient washout 5. With the wing on a flat surface, check

(twist) in the wing panels. the amount of washout at each tip. The
washout must be the same at both tips
(7/8").

Operating elevator and rudder control 1. Improper control surface throws. 1. Set up the elevator and rudder to move
stick results in jerky and erratic flight. the recommended amounts with full
deflection of the transmitter stick.

2. Insufficient or weak wing hold down 2. Attach wing to fuselage with at least
rubber bands may allow the wing to lift 10 or 12 good #64 rubber bands.
when making a tight turn or when
pulling out of a dive.

3. If the model is balanced more than 3. Carefully balance the airplane,

1/4" behind the recommended location, it front-to-back, at the balance point shown
will be too pitch sensitive and "squirrely". on the plan, 5/8" behind the center of
the main spar.

38
 GLOSSARY

AILERON: The hinged, movable surfaces on the trailing edge of the wing FORMER: A part that gives shape to the fuselage and also divides it into
that causes the aircraft to roll (bank) left or right. different compartments. Same as a bulkhead. Usually designated "F1",
"F-2", etc.
BREAKAWAY PLATE: A part, usually hardwood, to which the engine is
fastened by screws. The plate will "breakaway" in the event of a crash, FUSELAGE (FUSE): The body of the model.
thereby saving the engine from damage.
GLUE JOINTS: The area where two or more parts are joined together by
BULKHEAD: A part that gives shape to the fuselage and also divides it into glue.
different compartments. Same as a former. Usually designated "Fl", "F-
2",etc. LEADING EDGE (L.E.): The front or forward edge of a part such as the
leading edge of the wing or the leading edge of the rudder.
CA (CYANOACRYLATE): A glue that cures almost instantly to give a
strong bond. Thin CA seeps into a joint to bond it and thick CA will fill gaps PILOT HOLE: A small hole that is drilled to guide a screw into the wood.
at a joint. The hole is smaller than the screw diameter.

CLEARANCE HOLE: A hole drilled or cut in a part to leave room for RUDDER: The hinged, moveable part at the rear of the fin that causes the
another part (screw, etc.) to fit through it. aircraft to turn left or right

CONTROL SURFACE: The movable parts of the aircraft that control its SADDLE: The areas on the fuselage where the wing and the stabilizer rests.
operation: The rudder, the elevator, and the ailerons (some planes even
have flaps and/or spoilers). SPAR: A part that runs the length of the wing and acts to strengthen it.

DIHEDRAL: The angle between the right and left wing panels. STABILIZER (STAB): The fixed horizontal part of the tail section that
helps to keep the aircraft from pitching (climbing or diving).
DIHEDRAL BRACE: An angled part that helps to hold the wing panels at
the correct angle, and provide strength in the center of the wing. TACK GLUE: To glue parts together temporarily so they will stay in place
during another procedure. A very small amount of glue is used so the parts
ELEVATOR: The hinged, movable part at the rear of the stabilizer that can be broken apart later.
causes the aircraft to climb or dive.
TACK RAG: A chemically treated rag that is used to clean dust and dirt
ENGINE BEAM: A part, usually hardwood or plywood, rigidly mounted from the model after it has been final sanded.
to the fuselage that supports the engine.
TRAILING EDGE (T.E.): The rear or back edge of a part such as the
EPOXY: A two part glue consisting of a "resin" and a "hardener" that trailing edge of the wing or the trailing edge of the rudder.
when mixed together gives a very strong glue joint. Epoxy comes in
different bonding times: 5 minute, 15 minute, 30 minute, etc. TRAIL PIT: The attempt to fit parts together before you glue them to make
sure they fit correctly..
FINAL SAND: To use a fine grade of sandpaper to sand the airplane, after
everything is built, to get it ready to be covered or painted. WING PLATE: A piece of thin plywood that is glued to the top of the wing
to protect it from rubber bands or wing bolts.
FIN: The vertical stabilizer or fixed part of the tail section that helps keep
the aircraft going straight ahead. WING: The part of the model that creates lift. The wing can be mounted
on top of the fuselage, on the bottom of the fuselage or somewhere in
FIREWALL: A part, usually plywood, that separates the engine compart- between.
ment from the tank compartment. The engine mount or beams
are attached to the firewall.

NOTICE:
Add shear webs to the wing as described below (after step 17 on page 18)

We have included in this kit, ten 3/32" LEADING EDGE

Balsa Shear Webs which are wrapped in clear

plastic. We recommend that you add them as
described below as they will add strength to the DIHEDRAL BRACES
SPAR

wing which will help it survive violent manuev- SPAR

ers and crashes.

Glue a 3/32" balsa shear web to the WING ROOT (CENTER)

back side of the main 3/8" x 1/2" basswood spars 3/32" BALSA SHEAR WEBS SHOULD
DIHEDRAL BRACES
in each of the four rib bays shown in the sketch. BE ADDED IN THESE FIVE PLACES

Also glue one shear web onto the front side of the TRAILING EDGE
spars in the rib bay next to the dihedral brace.
These shear webs should be securely glued to the
spars for maximum strength and sanded flush
with the top and the bottom of the wing.

39
 PT40 PARTS LIST
PART NUMBER QTY DESCRIPTION PART NUMBER QTY DESCRIPTION

PT40F01 2 Balsa shaped 1/8 PT40F14 1 7-Ply 3/8x2x3-15/32

Fuselage Side Landing Gear Plate
PT40F02 1 Balsa Shaped 1/8 PT40W10 2 3-Ply 1/32 x 1-1/2x3/4
Fuselage Top Wing Plate
PT40F03 1 Balsa Shaped 1/8
Fuselage Bottom PT40A05 1 SUB PACK - BALSA
1 3-Ply1/8DieCutF2,F3 PARTS
PT40F05
2 3-Ply 1/8 Die Cut Fuselage PT40F04 2 Balsa Shaped 1/4 Upper
PT40F06
Nose Tripler
Doubler
PT40F09 2 Balsa Shaped 1/4 Lower
PT40F07 1 3-Ply 1/8 Die Cut Fuselage Nose Tripler
Bottom, Servo Tray PT40F11 1 Balsa Tapered 9/64 x 1-1/2
PT40F10 2 3-Ply 1/8 Die Cut F1, Stab Tail Wedge
Saddle, Lockplates PT40F12 1 Balsa 1 / 8 x 2 x 3 - 3 / 4
PT40F15 1 3-Ply 1/8 Die Cut F4, F5, Windshield
F6 PT40F18 1 Balsa 1/2 Tri 3-15/32
PT40F16 2 Dowels -1/4 Diameter x 25" Windshield Brace
Pushrods PT40R04 2 Balsa 1/4 Tri 4-7/8 Fin/
PT40F17 1 3-Ply 1/8x3-23/32x3-1/2 Stab Fillet
Hatch PT40S04 2 Balsa 1/4x1/4x5-1/2
PT40F22 2 Balsa Shaped 1/8 Upper Stab Tips
Fuselage Side PT40W11 1 Servo Rail Brace
PT40P01 1 Plan, Fuselage and Wing
PT40P02 1 Instruction Book PT40M02 1 HARDWARE BAG
PT40R01 1 Balsa Shaped 1/4 Rudder NYLON26 1 Nylon Strip Hinge, 9"
PT40R02 1 Balsa Shaped 1/4 Fin Rear RUBB001 6 #63 Rubber Bands
PT40R03 1 Balsa Shaped 1/4 Fin Front WBNT111 1 Wire 5/32 Nose Gear
PT40S01 1 Balsa Shaped 1/4 Stab WIRES16 6 Threaded Pushrod Wires
Front
PT40S02 1 Balsa 1/4x2-3/4x20-7/8 PT40M01 1 PARTS BAG - NYLON
Stab Rear AND METAL
PT40S03 1 Balsa 1/4x1-1/4x20-7/8 NUTS001 8 4-4- Blind Nuts
Elevator NYLON02 2 Nylon Control Horns
NYLON 16 1 Steering Arm
PT40W05 1 Balsa 1 / 8 x 3 x 1 3 Center
NYLON 17 4 Nylon Standard Clevis
Sheeting
NYLON20 2 Nylon Swivel
PT40W08 4 Basswood 3/16x3/16x30 2 Nylon Aileron Clevis
NYLON21
Front Spar 4 Nylon Landing Gear
NYLON30
PT40W09 2 Balsa Shaped 3/8 Wing Tip Straps
PT40W14 1 3-Ply Die Cut 1/8 Dihedral NYLON33 1 Nylon Nosegear Bearing
Braces SCRW002 4 2-56 x 5/8 Screws
PT40W15 1 3-Ply Die Cut 1/8 A & B SCRW003 8 4-40 x 1 Screws
Wing Braces, F-2A, F-2B, SCRW004 8 # 4 x 1 / 2 Screws
Gauges, A-3, B-3 SCRW010 6 #4 x 5/8 Screws
WBNT112 1 Wire 5/32 Main Gear SCRW020 1 6-32 x 3/16 Screw
SCRW024 3 #2 x 3/8 Screws
PT40A02 1 SUB PACK - RIBS WBNT110 1 Aileron Torque Rods, 1 Set
PT40W07 13 Balsa 3/32 Die Cut Rib, WHCL005 1 5/32 Wheel Collar
2 Per sheet WSHR002 4 #4 Washer

PT40A04 1 SUB PACK - HARDWOOD PT40W01 1 WING PACK

DOWEL021 2 Dowel 5/16 Dia x 5-3/16 PT40W02 1 Balsa Leading Edge,
Wing Hold Down Trailing Edge, Set
PT40F08 2 3-Ply 3/8x21/32x3-1/4 PT40WU4 4 Basswood 3/8 x 1/2 x 30
Engine Beam Main Spar
PT40F13 2 3-Ply 1/4x3/4x3-1/4 PT40W06 2 Balsa Tapered 11/32 x
Breakaway Plate 1-3/16 x 30 Trailing Edge

- IMPORTANT NOTICE -
TO MAXIMIZE THE "SELF-RECOVERY" CAPABILITIES
OF THIS MODEL, TRIM THE ELEVATOR AND RUDDER
FOR STRAIGHT AND LEVEL FLIGHT AT 1/2 THROTTLE.
Slide the slllcone bands over the
Beginners: Please show this notice to your instructor. nylon clevises to insure that they do not
pop open during flight.